Why does "everyone" like or dislike X or Y (now)?
Because they do or do not, move on and shut up.
How come "nobody" plays X or Y type of RPs or does (not) add W and/or Z (anymore)?
Most things are unused or disliked due to player unfamiliarity or the assumption that fellow RPs can not be trusted with what they are given.
As for likes, people like what they like. RPGuild has fads and phases like any other part of the world, some people like them and others don't, but there isn't a need to Raise-Cain about it.
They either do and you're being too anal about your requirements for joining an RP or you didn't see that one gem that was posted a couple/few days/minutes ago and must go hunting for it, now.
You can also try making your own RP or talking with some friends to try and make your own, because complaining about it wont help.