It occurs to me that people probably think I am saying they should change the type of RP overall that is going on. For those that feel that way, let me quickly clear that up. Basically, I am advocating a different approach to the whole matter.
In a perfect virtual world all story are coherent, but my point of view I don't feel like coherence is a primary goal to reach in a virtual world. Also striving for coherence at all costs usually gives all sort of problems like explaining perfectly how magic works and usually it fall-back to creating a "too much" real world with real life physic, real life issues and all sort of things most of us want to leave in real life when playing a game.
I think where coherence leaves some gap creativity fills in the rest. Same can be said for setting: where minor things are unclear that's where players can step in and create their own explanations. This gave birth to many interesting RP in my case.
About the community I think the respect for each others is its main glue. More than cohesive RP. if I feel respected OOCly and I feel other players are willing to open me the doors to their rp (even if I don't like it) and don't let me down just because I don't feel like to join it, well I would stick with such community 
Umm... This one I have to disagree with in certain places since it kinda goes inherently against the nature of storytelling. I don't care how much respect for each other two authors have or how much goodwill there is, if they write stories with a different nature to their worlds, that is the fundamental baselines are different, those stories won't mesh until you reconcile the differences. Yes you can mix characters, and genres and so forth but I don't care how much you try to push Avatar's story line and Twilight's story line together, you are going to have to decide on what to keep and what to toss to even begin trying to fitting the story together. And yes, even in PS RPs can be that wildly different. Further, coherence doesn't imply you have to agree on every little thing but one great source of tension did happen to be from the settings team not being able to address certain things and then players getting offended when the settings was finally addressed and their individual explanations no longer fit. If even official settings isn't allowed to come up with an explanation how would it be any less messy when it is between players who have the same amount of authority on the matter?
While I'm happy for you that just the OOC understanding is enough, I don't think that it is enough to form an RP community though it is most assuredly critically important to keeping OOC cohesion. RP is not OOC so OOC will only help the story aspect so much. But the OOC understanding really must be there or you have the same problem with community but for a different reason. I believe what made PS popular in the past was that you could feel distinctly that you were stepping into a large story, a dynamic one, and not just a visual world. If everyone is kinda doing their own thing, traveling between RPs is more like island hopping than exploring a whole world. And one can easily get lost in the cracks.
All I am trying to say is that island hopping is not bad, but you loose a lot of potential than if you were to have a continuous landmass. All those gaps in between the "island" are those interactions missed due to not caring for a continuous story. For instance, Illy was about as lawful good as PS characters came, but her life regularly intersected those that weren't and she regularly dealt with them. Why? Because all the characters were interconnected in one great big on going story and they were dynamic enough to have more than one way of relating to their environment. And it wasn't a "let me stop/finish this plot and join another plot" story. Their stories flowed into each other. These characters had lives that told a story instead of just episodic bursts of "something happening" in their lives. This is what I mean when I keep bringing up storytelling in general.
Further, and I know people don't like to hear this but it's still a valid statistic: Planeshift's average player count is about 40 and that is with a regular trickle of new people coming to look at the game. What is going on now is simply not enough to hold the attention of enough people to grow the player base. Yes there are a variety of factors, like the short attention span of the average MMO player, but keep in mind two things:
First, planeshift grew up from a playerbase that was smaller than this one, it had less to do, and even less RP

, yeah I said it, but it grew up to eventually get as high as 200 players online during the day... And there were still factors then, as now, that made it unlikely that the player base would have grown. But there was enough there to keep people's attention and to make pretty loyal players who put up with a lot even if not everything. When people have something to latch on to, they will latch on and they will hang around even when it is inconvenient. I put newer players on my buddy list as I interact with them and as it stands my buddy list still stays pretty red. Anticipatory side note: there are many people out there with computers that can handle the game's requirements and that also RP. Even if former players couldn't run the game there would still be new players that could.
I guarantee you that at the rate it is going, PS is not only not growing, it is shrinking and will keep on that way. The highest player count of the year should be during summer when people have the most free time, not winter... It basically has to go down from here until next summer. Whether older players were elitist, had their heads too far up places we won't speak of, or whatever, there is something to be said for the results. That's why we call them results. I stick out as a note though that the reason the numbers came down at all was that lack of OOC respect between groups. As I said earlier, it is critical, but it's not enough on it's own either.

Second point, graphics and visuals are nice but are less important in a RP world, the charm and compelling story are the sticking points. In RP, the story is less the sum of the building shaped boxes and pointy objects you can stick into mobs and more the character's and their interactions with each other and their circumstances. You can take away the items, the maps, and a character model and what would be left is the story much like the ones written here on the forums. Now take the RPs going on in PS now and string them together end to end... Would that story look like a continuous story or would it look like a few storylines stuck parallel? Would it look like a full world, or would it only show a certain segment. I know that you can never achieve full continuity, or address every aspect of every character's life, but it can be done more than it is currently.
Look at games like ADOM and Nethack, they aren't RP games but they are ascii games. That's is as low graphically as you can get.

They have a distinct story or perspective for you to advance with a great deal of thought put into it, which is more than a lot of graphically more advanced games. And a far larger player base than PS... The reason I even bring these games up is because often people want to cite newer MMOs as being a reason for PS's player decline, or that focusing on graphics and skills will fix that... These games are rather simple compared to PS, but they maintain more loyalty through engaging the player in the world more. If games like this which are not specifically for rp can do it, shouldn't it be that much easier to do in PS where it is set up for you to be able to create stories together?
In the end, I imagine it's a we agree to disagree matter. But I think adding more concepts of traditional storytelling would flesh out PS, allow for a more full feeling world, give newer players something to latch on, and give existing players more to work with.