Manchester U was in better shape sans-Beckham then they were with Beckham, not to mention the fact that the $$ they got as a result couldn't have hurt them.
A lot of teams CAN fix things by throwing $$ around, they just DON'T (I'm talking to you, Montreal). Steinbrenner throws obscene amounts of money into the Yankees, and it shows in the form of championships, television networks, and a new stadium (planned for "across the street," currently). All three of those things foster a larger fan base, and sold out games -- all adding up to more $$ back. He spends more to get more.
Again, the true problem here is not that Steinbrenner is doing the things he does, since it is completely legal by league rules (the profit sharing BS doesn't PREVENT him from spending, it just "punishes" him). The problem is MLB rules. Blaming Steinbrenner is like blaming a Mormon for having multiple wives... it may be immoral by your standards, but it's completely legal by the Mormon rulebook.