You have one side who want a game about controlling a giant robot to be fast, fluid, and basically control exactly like a 50ft tall Raiden doing ninja flips and ignoring all laws of physics
Then the other side who want World of Tanks autism simulator with legs (for some reason)
Anything in the middle makes both of them mad, and there are not enough of either audience to justify making anything catered just to them.
So we get no mecha games until every decade or so someone makes something in the middle again, piss both sides off, then another decade of nothing.