I don't think there is anything inherently wrong with a three tier system. If it works well, then it can expand distribution and provide more beer choices to customers. In order for the system to work, if the three tier system is mandated by law, the three tiers have to be truly independent. When they aren't anticompetitive practices occur and you and I, the end users, end up with fewer choices.
Craft brewers like Sam Caligione aren't afraid of competition, in fact, they welcome it. The problem arises when huge companies wielding awsome amounts of power and money abuse the system, and I think Beer Wars provided many good examples of exactly that happening.
I respect property law and a legal system that protects intellectual property rights is hugely important; but the legal system can also be abused. Look at the patent trolls, the RIAA etc.
I thought Beer Wars showed pretty clearly a lot of the anticompetitive activities of the BMC. From frivolous lawsuits over the words "punkin" or "monster", in which the BMC win even when they lose simply by causing small microbreweries to have to expend huge amounts in legal fees just to defend themselves, to providing free kegs of beer to restaurants provided the restaurant doesn't stock "that other caffeine beer."
That is not competition. That is pure sleaze. And it happens all the time. The antitrust laws are in place specifically to prevent this kind of activity.
Do you think it should be legal for Miller to go around to all the bars stocking your favorite microbrew and provide them free kegs of beer until your microbrewery is driven out of business? They have the kind of money that they could and probably would do it if they could get away with it.
The three tier system is the same way. If the BMC didn't see themselves getting an advantage out of it, they wouldn't support it. They don't care about you or I getting a good selection of beer. If they had their way, we would only have the choice between Bud and Bud. They support the three tier system because, in general, the distributors are beholden to them and make sure their products get sold first and in the best slots.
So long as breweries are required by law to sell through a distributor, BMC is going to dominate the markets - and its not because they sell a superior product.