The characters never evolve and eventually they grow tiresome when their storylines only revolve around one issue. The ironic thing about the Warren-Bobby attraction thing is that way back in their Champions/New Defenders days, Bobby used to bring home girls who were only interested in him because of Warren.
The Revanche/Psylocke storyline wasn't that bad in X-Men 31-32 but the fact that almost ten issues earlier Nicieza had tried to resolve that storyline only to realize he had completely messed it up and needed to retcon his mistake made it really difficult to absorb. I'm not surprised he got a lot of criticism over it from readers. Also, frankly Revanche's introduction never amounted to anything. She was barely around and even when she was, she was reduced to wallpaper and never had any major story or emphasis beyond being introduced and then dying. I didn't even remember the whole storyline about Betsy in the afterlife until you mentioned it.