I have my own issues with Warren Ellis' run on Excalibur. I liked how he wrote Kitty, and Pete Wisdom is a cool character when written well(ie, not written by Ben Raab!) but I never liked them as a couple. I have the same problem with Buffy and Spike. That's just my bugaboo, I'm not flaming anyone.
What I really hated was his mishandling of Colossus. Given that in Piotr's most recent appearance prior to his stint on Excalibur(UXM #325) he wasn't even thinking of Kitty. He knew he had made mistakes during his time with Magneto's Acolytes, and wanted to atone for them. Had Ellis read that issue before writing him into Excalibur, I don't believe that he would have written him as an unthinking brute, attacking Wisdom for daring to lay hands on "his Katya".
In later issues, Ellis wrote Piotr as the thoughtful, kind-hearted, gentle giant we all know and love from Claremont's run, making it hard to reconcile that treatment with the way Ellis wrote him when he first joined the team.
"Them's my beliefs, amen, so be it." --Long John Silver, "Treasure Island"