Yes, revenue sharing has always been questionable at best with the Marlins, Royals, Tigers, and Pirates. They've historically spent less than 40% of their share of the revenue from the league, but Jeffrey Loria has put everyone else to shame by spending about 15% of the nearly $300 million the Marlins have made since revenue sharing was increased. He's pocketed the rest of it.
I've literally never heard a single person describe the game of baseball as a shame sport. Sure, extremists would say something like that in regards to steroids, but to be honest, that opinion doesn't matter a whole lot when you consider that baseball is one of the lowest paying sports per player because they don't have a salary cap.
MLB absolutely does need a salary cap. While there are a few teams that don't spend the money they make in revenue and luxury tax income, the underlying rules for revenue sharing are so otiose it's a joke. People are justified in criticizing the Yankees and Red Sox and most of the other large market teams because they fucking work the system. The New York Yankees just last year opened a new stadium which will in the end cost the city almost a billion dollars to finance, with the Yankees picking up somewhere between $100-150 million over 25 years. The team keeps all profit from the parking structures (something only one other team, the Red Sox benefit from), and are tax exempt in the state of New York on all goods and services they provide. That is the most quintessential form of an unfair advantage that you'll find in professional sports.
No other teams outside of New York, Boston, and Chicago have the benefit of receiving tax exempt status. Teams make on average about $206 million over the course of the season. Take out the average of 8% commerce tax from most states, you're looking at about $190 minus their share to the league on goods puts you at about $160 minus the league average $84 million in salaries for players you're looking at $76 million, then you take all of the salaries out for stadium expenses, and you're looking at about $35-40 million. So in the offseason, one could expect an average owner to have approximately that much to spend on new players, which with contracts where they are now, is about 3 Free Agent contracts. The Yankees and Red Sox on the other hand, average about $350-375 with all of the benefits they enjoy. If any other team in the game had those perks, they'd be spending the money the Yankees do. Problem is, no one else gets those perks.