If your the worst on the best, you get the same amount of money, maybe even more. Most teams that are bad cannot afford good players. However, if you were on a great team, and you won a championship, you would get a championship bonus, as well as a possible extension, endorsement deals, etc.
Also, self-esteem is a big issue. If your team constantly struggles, you will probably feel you don't belong on the team. You will almost certainly demand a trade or signing bonus, while you are still getting mad at your team and coaches. It would be much better being in some form of spotlight, like winning a championship. You could still get a good salary, and feel like you accomplished something.