Tanks were being used as the endgame for selfish solo players who wanted to be the 'complete package' without bothering with all of that annoying teamwork stuff (because why work with others who are clearly not as good as you! (they shouted from inside their tanks!))

Now they're where they should be. A single part of an effective force, that can't just be deployed in every situation regardless of context. A lot of people didn't take well to that, but luckily after two solid weeks of allcaps bitching they decided to give something else a try and might even be having a pretty good time instead of shooting blood out their eye every time they get gangbanged by swarms.