here's my take. i think although it is in the rules to be RP, people don't obey them outside central zones (and even then, not all the time). for this, i don't think it's the cause of a low player base.
what i think's the cause is that it IS an rp game - it's not meant to be like other mmorpgs. i see it as half a conventional rpg and half a rp area. also, think about it, have you ever seen PS give you a better reason to give you money other than "it'll help out PS as a whole" which, though VERY honorable, doesn't lead to many upgrades on the game's part. for this, i commend PS for not selling out. i honestly don't get how it's still up and running w/ how little money it brings in. PS doesn't have a $100,000 budget to keep up w/ new game trends and a $50,000 budget to advertise. this is why we have few players.
nonetheless, it's VERY impressive what you've done, devs. every time i see PS i wanna rip out 3ds and photoshop and help in the work
thank you, donaters, we love you