1. McHale is a big man.
2. Hakeem Olajuwon is around to mentor
3. Gateway to China
4. Income tax.
Now about the income tax deal. I know the Lakers could have offered him more money, but people forget that basketball contract is not the only income Dwight makes. He will make tons more in endorsement contracts that will not be subject to income tax, therefore the no income tax in Dallas is a major major saving for Dwight.
5. He does not have to follow in Shaq's footsteps.
6. He told Lakers last year he did not want to be traded to them.
Finally, can we get a booster rule in NBA like in College. It seems to me that the NBA Anti-tampering rules can be circumvented by using agents to recruit other team's players. For instance Hakeem Olajuwon luring centers to Houston by promising to mentor them. If this is done while player is under contract is it not tampering?