Serious question: Why haven’t the Texans talked to Leftwich?

Usually the OC for a Super Bowl winning team gets to be highly sought after for a HC gig. The guy has been OC for 14% of the leagues 5k passing seasons and doesn’t come with the same baggage as Bienemy. Dude clearly doesn’t want to work with Baalke but wants a HC job so why not give him a call?