MAVS NEWS:

[omahen]

If the Adelsons wanted a team in Vegas, they could have bought the upcoming expansion team. 

While I don't believe the move to Vegas is the reason, just for discussion purpose. Also I can't judge if or why a team in Vegas would make more sense than a team in Dallas.

The counter argument for the sentence above I think is simple. It is not easy to buy a team, many others want the chance. The expansion itself is also nothing set in stone, only some rumblings that it might happen someday. So no guarantee they would succeed in getting that expansion team if it happens. Mavs were on the table and they took the chance. They would prefer to move that to another location.