I am not in favor of a cap whatsoever. We live in a country where you have the freedom to work where you want and make as much as possible. If millionaire and billionaire owners can, why can't players? Every person who watches a baseball game, attends a game, buys a hat or shirt, or any type of MLB merchandise is contributing to the salaries. The more popular the game is, the more money is going to be made. The owners don't go out and perform, players do.
Most people don't know that MLB has a luxury tax. Teams like the Yankees and Red Sox pay penalties every year for spending over a certain amount, which then gets distributed to smaller market teams to use. There also is revenue sharing. The problem is, a lot of the other teams which receive this money DON'T use it towards acquiring players. There have been reports of it being used towards Christmas bonuses or just pocketed by owners to make their bottom lines look good.
If you are a Yankees fan, how can you not love how the Steinbrenner family spends their profits to put a great team on the field, when they could easily just pocket it? Conversely, if you are a Pirates fan (a team which consistetly receives revenue sharing and luxury tax money), how can you condone an owner who touts how his team is "profitable", yet sells/trades off players and won't sign even B level free agents? They haven't had a winning season in over 10 years. Yes, baseball is a business, however if you are an owner of a team, shouldn't being competitive be your number one priority? As long as you break even and don't lose money, all baseball profits should go back into your team to make it better, not back into your pockets. If you can still profit enough to pocket, great. But, if you're a team like the Pirates, do your fans really want to hear each year that at least you're profitable?
Look at the NFL where there is a cap. Look at the massive TV contracts and licensing. With a cap, who is getting that excess money? The owners. While retired players, who made the league what it is in popularity and money for the owners, are having myriad health issues from abusing there bodies in organized body to body combat week after week. Were they well compensated? Of course. But, what did the owners do more to get a much the bigger slice of the pie for all these years? Just remember, if the NFL salary cap was so great, the NFL wouldn't be looking at labor issues coming up, and the real threat of a work stoppage.