I wasn't reading comics at the time, so no comment on the execution, but I did hear about the move to sideline mutants and promote Inhumans, and I actually liked the idea.
I've never been much of an X-Men fan. I initially found the origin of "they were just born that way" to be lazy, and eventually watching them just drift away from what I even thought a mutant was with secondary mutations and omega level mutants and then Namor was a mutant. Maybe it made sense when reading it, but whenever I'd see something like "this is Bishop, he carries a gun," or "turning to diamond is the natural extension of my telepathy" I was even less tempted to read it.
Anyways, I'd always found the Inhumans interesting (as a concept at least, apparently their only story was "Maximus is doing something"). Creating a big event like the terrigen cloud floating around the world spontaneously activating people with unsuspected Inhuman genes was at least an inciting incident that "I was born this way" didn't have.