I would guess Tilman isn't as liquid as he once was and is tied up with his take private of Landry's, amongst other things.
1. Fertitta didn't have the money. To buy a MLB franchise, you need several hundred million dollars sitting around, that you won't even notice is missing. They won't let you have a team if you have to scrounge up change for the purchase price.
2. Fertitta has never really been liquid. He's always been in debt up to his eyeballs.
3. After he went into the casino business, they'd never let him own a team, even if he *did* have the money.