i think the trouble come from the fact 2-3 community did meet with differentes expectation for the game, leading to some clash.
first you have the new player, the one that have little to no experience in mmorpg.
second you have the people that did play mmoprg in the last 10 years (mostly WoW period), that are called the "modern" mmorpg.
finally you have the people that did play for a long time to the mmorpg, often coming from game like FF11 and looking for an experience close of this.

sadly the game is more oriented to the modern mmorpg (with it bad side, we can't denie that did bring a lot of bad side) and for the new player.
the modern mmorpg focus on get into the game fast and enjoy it even if you don't spend a tons of time into it.

in other word, the community have trouble because veteran, Hardcore gamer and new player can't accept that the other have the right to enjoy the game. without forget, that the mmorpg, have evolve into what we have today. some people don't accept this, they want to come back to an age that have end. some want extremely hard content and other want long content... but develope a game that only a small part of the community will enjoy is not the goal of yoshida... and until people accept it and accept the other... the community will be caustic.