I think the big problem in this thread is the blockchain itself, the whole conversation would be much easier if we just talked about decentralized mmorpgs.
Decentralized mmorpgs are hard enough to do right when one entity (company, individual, etc.) owns and operates all of the servers. I grimace at the thought of trying to pull that off when there is no single trusted entity (a base assumption of virtually all decentralized systems at some level or another). Literally every single interaction that's trivial to get right on a single-server MMO is 10x (or more) harder to get right when multiple servers are used to scale a single game world, and multiply by 10x or 100x again when those multiple servers can't be trusted. You also get into some weird questions with decentralized designs that don't come up when you assume a single controlling entity. For example, decentralization usually implies no single owner/authority (and most decentralized computer systems assume that at some level in their design), but mmorpgs virtually always have a single controlling entity. So what happens if there's a conflict between, say, 55% of the controlling population and Atomic Blue? Depending on the decentralized design, that might be enough to convince the computers that the 55% are "right" and that the game should follow that path - but Atomic Blue holds the rights and intellectual property of PlaneShift, so they're the owners and thus have the right to all final decisions. That's one of the easiest problems I can think of solving, too - when you assume that some of the people holding the keys to portions of the decentralized system might be willing to budge things around to cheat (duplicate rare items, increase currency balance/stats, etc.), it gets reaaaaaaally nasty.
Blockchain is just mediasexy word, it's not that amazing at all people just hype it for no specific reason (i guess it's cause bitcoin or something). It either dies in few years or sticks to some communities to plague the world.
I'm Ecthion Felagund and I approve this message. Vote Ecthion Felagund for no more blockchain! (Ok, maybe not entirely - it's a fascinating technology that has a lot of possibilities in a few areas... but I agree with you that it's freakishly overhyped.)