This idea makes sense in theory. However, like hrudey said, you'd then also have to think about increasing all-star player's salaries next season, kind of like how NBA players often have bonuses or other clauses that earn them money for achievements like being named an all-star or scoring titles. Not sure we want to pay higher salaries.
Also, for some people, some of their best players are their trainees, who may play only one game per week as they try to get multiple players 48+ for single-position training. So it penalizes teams that train top talent, because they are less likely to get all-star votes and thus miss out on extra revenue. Then there's the question of LI teams not getting a fair shake in the 3-point contest, and how offenses in general affect voting and such. So basically, I think it's a nice idea but really hard to implement fairly.