That's a fair assessment on Morrison's run. I also think he added a lot of interesting concepts: secondary mutation, Kick, Nova, the mutant culture, the school finally being a school, a Riot at the school.
On characterization, tho, I think Morrison wrote Xavier, Nova, Jean and Emma really well. "Just" the non-telepaths that were all stupid.
Scott especially was very poorly written. His tantrum and running off to the Hellfire Club were so Austen-like.