The dream of Mythic is basically dead... Frost Interview with Yoshida

[Shurrikhan]

it's become a part of Warcraft's underbelly black-market where players sell key runs for gold and RMT.[/I]

The majority of WoW's RMT still goes towards raid clears, probably followed thereafter by arena carries. Paid clears/carries have been a thing since Vanilla. Heck, there are even sales for Torghast (casual side-content). So why are we uniquely blaming one piece of especially accessible / long-scaling content like M+ for a game's run-sale culture that predates it by a dozen years?

Mythic 4-man dungeon's

5-man.