I also had a bad experience on Alaska Airlines. Instead of allowing me to stay in my own wheelchair until they transferred me into an aisle chair to get me on the plane, personnel insisted on transferring me into an airport wheelchair (which did not fit me at all) and I had to wait in it in great discomfort nearly 2 hours (because I always try to arrive early, of course) before getting on the plane. Since plane seats themselves are pretty uncomfortable for me, by the time I got to my destination, I was in agony. Also, the people who transferred me to and from the aisle chair seemed to be clueless about what was needed and seemed to have no training in dealing with people with disabilities. I did complain and got a coupon for $50 for my next flight on Alaska. But, since I am never going to fly them again because of their policies, that’s a coupon that will never be used.
FWIW, despite their seemingly poor record, I have STRONGLY preferred travelling by Southwest Airlines for the last 15 years and have never had any major problems. The training they give their personnel on dealing with disability issues is excellent IMHO.