What outdated game mechanic should be retired from MMOs?

Returning to an old game is like hopping in a time machine and surveying the horrible mistakes made by MMO studios a decade ago. Forget those five guys who still murmur the word "permadeath" wistfully; we're talking corpse runs, vitae penalty, corpse looting, tank mages, experience loss, holy trinities, zone walls, hybrid class level penalties, and tree-top cities without railings, all as a matter of course for the games of the day. Nowadays, these mechanics are abandoned in a field somewhere by all but the most retro game studios.

I have to wonder what we'll look back on in another 10 years with the same feeling of "wow, I can't believe anyone thought that was a good idea." Cash shops? Flying mounts? Faction-grinds? Classes? Skill bars? Questing? Tree-top cities without railings? (Seriously guys -- stop making those.) What game mechanic is so outdated and so abhorred that it should be retired from MMOs right now?

TH

PvE

IMHO gear dependance to level. I would love that armor weapons would be only cosmetic and that you could mod them (i liked that in swtor). Because many times i needed to change piece of equipment that i loved only because i outleveled it etc. I think that way game would be more interesting, because people could gather their own "Epic set" for End game.

I would have to side with gear dependence and grinding when it's not for the purpose of lvling up.