You can't do anything to influence Blizzard at this point.
They can shut down WoW retail and still do pretty well with Hearthstone, Diablo, Overwatch, HotS.
They did pretty much the same with StarCraft 2, i.e. sank it completely and nobody cares about it anymore.
The only thing you can do is to boycott all Blizzard's products.
The only way to play vanilla is to host it beyond the legal reach of Blizzard.
That's it.