I daresay your guildmates are severely misinterpreting the purpose of PS. The purpose of PS is not to rank up as fast as possible. It is also not the goal of PS to engage in PvP or other forms of directly comparing your assortment of skills and stats to of other players. This is contrary to all other MMO"RP"Gs I know of, and the confusion about it as well as the difficulty players who have come to PS from any other such game is understandable.
The purpose of PS is to RolePlay, and to do that, you do not need to rank up fast, or at all. Of course, skills are part of the roleplay, but they're far from paramount. Therefore, PS is playable even without the ability to fight MOBs, at least for some time.
Also, while the question of fairness is valid, these instabilities have been there, to various degrees, ever since fighting was implemented, so those who were there before you have had the exact same problem as yourself. Thus, the unfairness lies in you coming later than they, which you will agree is unavoidable.
I do understand that this is annoying if your emphasis lies on levelling, but if it does, then you will become frustrated and bored by PS fast anyway, regardless of how well the fighting works because there isn'T really that much to train, even if it's becoming more all the time.
Sadly, the situation is unlikely to improve, because of the way PS works. If PS was a commercial product, then you would not have heard of it until in, say, 5 years time, when it was more or less complete. It would also be developed faster, and with a distinctly different emphasis (IOW, it would not actually differ from any other MMO"RP"G out there).
However, since PS is being developed by volunteers, in their spare time, without requiring payment and in fact relying on the server and the bandwidth being donated by hosting companies, plus the fact that PS is pre alpha (meaning it's far from completion and really barely started), it is in fact impressive that it's as good as it is right now. Therefore, the situation is not going to improve until much later. I assume that in 10 years or so, PS will have reached a state where it will really be one of the higher priorities to keep the MOBs working in combat (right now, the emphasis is on trying to keep the game server from crashing every few minutes).
Edit: Additionally, please note that PS has and will have various bugs that can make you lose items, money or stats, make quests unsolvable or not even allow you to log in for days. There will also be partial or complete wipes, usually in response to exploits, or transitions to different database structures. All of this is what playing a severely unfinished game brings to you. /Edit
Also, what guild are you in? There are many guilds in PS that revolve around the concepts borrowed from other MMO"RP"Gs (levelling), but there also are some that actually focus on what PS is focused on: RP in the true meaning. It may be a good idea to switch to one of those guilds, which will 1) relieve you from the burden of being judged by your level and 2) not depend on the menial task of killing all day.
Lastly, did you really mean to say that not displaying the message would be a good alternative to having the problem fixed?