I actually like B2P MMO's as i absolutely hate to be bothered with money transactions in game.
With that said, its always a problem for the market because no one is willing to have more than one sub running.
With WoW declining maybe games like FFXIVARR and TESO will have a chance. Another good model is the hybrid SWTOR has. Actually i think thats the closest to beeing perfect because it doesnt pressure you to sub, but gives you benefits for doing it (like not beeing bothered by the restrictions/money grabing in-game). Those that dont mind it can still play F2P.