earn all that much money. its one things to get yanked around the country when you're earning a million dollar salary. That is less appealing for a 70K salary.
The pay is so much larger in the other usual U.S. leagues that the players unions agree to things like the draft. I think big market teams would be happy to get rid of the draft, but small market teams and perhaps league governing bodies that prioritize competition parity would usually fight to keep the draft.