There was no reason to rewrite the gamepad plugin from scratch as I understand it it works well most of the time. Also it makes sense to pull most things over from c2 to c3 since one of their goals was the ability to be able to import c2 projects into c3.
Anyways if there's an issue with the plugin with a certain controller then a bug report would be a good start to improve that. Likely the plugin works perfect with the controllers tested with so maybe there were edge cases with others.