X-men books mostly are self contained, that was how the X-franchise was developed so that would not have been a problem, the issue was marvel didn´t just push the inhumans, they did so in a way that confronted them with mutants and made it seem like it was zero sum game of us vs them. They could have used that kind of push to actually develop more stories for the characters and yes have them develop lasting links with the other marvel universe characters not just confront it them with the X-men. It´s the difference between a storyline developed because it makes creative sense and one done with commercial reasons behind it and the result is that commercial reasons alone are not enough fuel to tell good stories.