Interesting how you blame antisocial WoW on decline of subs. Yes, I know you want your arguments to win, but this is ridiculous.No, this is wrong. We learned WAY back with Diablo 1 in 1996 what happens when players get all the choices they want, and the outcome is a disaster. Diablo 1 was client-side only. So what happened was everyone immediately hacked the game files, gave themselves god mode, bypassed THE ENTIRE GAME, one shot Diablo in 5 minutes and then said "this game sucks" and quit.
THAT experience proved to everyone that the concept of "choice is always good to have" is a rotten concept. Diablo 2 was designed with a mandate to strip away choices. Specifically, strip away enough choices so people cannot just bypass the game and one shot everything. So Blizzard gave us the client-server model, where there were realms where Blizzard could limit your choices and patrol for hackers and cheaters. Taking away choice was universally recognized s a GOOD thing to revitalize the game.
The social issue is a LOT like that. When players get the option to be antisocial, they all wind up taking it, and it actually ruins the game, just in a different way than hacking does. Without the in-game community, the game stops having meaning. You achieve things, but for too many people, there is no one to share those achievements with. Attempts to lay the blame on the players for not socializing on their own fall flat, just as they do when creating a client-only game and then blaming the players for hacking.
Unfortunately, choice MUST be restricted for the good of the game by creating a server-client model to block choices deemed unhealthy like hacking. But just as important is to remove and disincentivize antisocial playstyles because in-game community is critical to success.
Proof of that is how subs grew constantly in vanilla and most of BC until they started demolishing the in-game community late in BC. Destruction of the community was in full force in Wrath. During Wrath, the playerbase growth stalled and leveled off because while Blizzard was destroying the in game community, the work had not been completed yet and parts of it still existed. Wrath benefitted from the last vestiges of the ingame community built up over vanilla and BC. By Cataclysm, the community had collapsed, and subs began their descent.
Blizzard attempted to arrest sub loss but has so far been unable to correctly diagnose the problem. They thought the problem was leveling needed to be streamlined and made easier. Wrong. They thought it was to make raiding more accessible. Wrong. They thought making a minigame like garrisons would appeal to lots of players because it was easy content. Wrong. They thought being SAVAGE with lots of wild orcs would fix it. Wrong. They thought adding demon hunters AND adding loads of endless content in legion would surely fix it. WRONG! We currently sit at around the same subs as we had in WoD.
The game needs the community back. Only that will fix subs.
Subs went down for many reasons, sure, some of them are things you said, but same things might attract different kind of players.
Overall, you oversimplified the problem and turned all the burden on antisocial.