Allen I think is the only real reason a team is not already there, I agree with you.
Well, he controls the arena, much like Les Alexander did in Houston. If he doesn't want an NHL team, there isn't going to be one.
Economics in Portland, don't make merely being a tenant in the Moda Centre in Portland, a sound business proposition.
That's why, the situation in Phx/AZ is what it is. NBA owner doesn't want to share an arena with the Coyotes, to ensure that they control all of the revenue streams. NBA knows that the NHL team has to make a decision as to their future very soon. Sun's lease still runs for a few more years. They can simply out wait the Coyotes.
Allen could have gotten an expansion team back in the late 90's with Minny/Nas/Atl (likely would have beaten the CBS application) if Allen really wanted a team. He doesn't, and never has expressed interest. With the NBA and NHL seasons running basically concurrently, economics might not be the best to have an NHL team.