Its because its new and people dont like new things, but i also do believe Nudge is a little Op atm, its very easy to spam it over and over again. But saying that, people are starting to find out a way to counter it, i've encountered a lot of people kicking and nudging back, if someone is up in your face and they ahve a 1h, you know they are going to nudge you, just kick.
But i believe a small nerf and time for people to get used to it being part of the game should do. It a very cool concept but i thiink it would be a good idea to remove it until all classes have it