UA must not like AVL (or isn't making enough money on those routes).

I think it was sometime last year that they stopped flying IAH-AVL.

Just for fun I pulled up some fares for IAH-AVL in early November. Can choose to connect in ORD (with a CRJ200 for the second leg!) or EWR (ERJ145). Fares start at about $650. Travel time is 5h 40m plus depending on the connecting flight.

If I switch to IAH-GSP there are 2 direct flights a day with a fare around $320 or so. This matches the fare for WN who has 1 direct flight a day from HOU. Fortunately my family is about equidistant from both AVL and GSP.