Originally Posted by
Kralljin
Remember what happened to 10man heroic? They didn't just aliente those, they told them to recruit 10 people, fuse with another guild or fuck off.
I would argue that the total amount of 10man heroic raiders was greater than the total amount of 25man raiders by the end of MoP.
Unless you're a Mythic raider, M+ effectively replaces raiding, that's why heroic guilds seem to vanish, because there is no incentive for anyone to set Heroic as their endgame - you get your loot from M+ already (or even freaking WQ's right now).
More game modes sounds fine on paper, but if all game modes award the same type of currency in similiar quality, you'll sooner or later see people gravitating towards a path of least resistance.
M+ is the path of least resistance because it requires less people, we are repeating history here right now.
In a social game such as WoW, you'll see that people basically face a choice, attempt to pull through and keep going or go with the masses, most people choose the latter.
The point is, you need other people to play with you, if you have trouble finding people to raid heroic in an organized manner because M+ basically feeds them their gear, you'll have difficulties to stem a roster that isn't basically a pug raid.
Unless Blizzard creates clear cut barriers (like they did with PvP until Legion), the raiding population below mythic will further dwindle due to M+.