Byrne left, and Claremont's ADD had the run of the place.
I do not think that most people realize the amount of influence to the story that Byrne actually contributed.
whatever the case, I agree that everything after byrne stunk terribly.
Most overrated series of all time.
I find Claremont's work without Byrne to be quite cold and soulless. Also, overly verbose. I recently re-read Avengers Annual 10, which was quite ridiculous in this respect. Michael Golden did some great, detailed art in this book, but the panels often look almost miniaturised because of the writer's word density, and best magnified on a tablet to appreciate them properly.