Do you think they should cap how much you can spend on your team? I guess there's a cap on individual player quality, right? In any given level a player can only be trained so much , to 9 stars, and then he just can't improve anymore? So technically there is a cap on what a person can spend on a team. It does seem terribly unfair though, but I don't see them doing something to further limit how high a team can go, which in the process would make them less money.
I guess you've just gotta suck it up and take the hit.