I think that you're going to see more and more of this, fans be damned, in the future.  Besides being potentially profitable from a financial standpoint -- you can debate whether or not an all-Cardinals station is going to attract listeners, especially in the offseason, but in a case like the YES Network it seems like a winning proposition -- having control of the entity that broadcasts your games allows you to shield your profits from the revenue sharing rules that the league has in place.  

Consider it money laundering for teams that don't want to give idiots like Carl Pohlad part of their hard-earned money each year.  I guarantee you that the Tribune Co. (WGN TV and Radio) pays the Tribune Co. (the Cubs) less than market value for whatever portion of games are still broadcast on their stations these days.  This reduces the amount of profit that the Cubs see on their bottom line, and reduces the amount that has to go into the revenue sharing pool.

It's a shell game, and as long as the money that the Cubs would have gotten from selling TV rights to a third party is less than the sum of the money they get by selling ads on WGN and the money they save by dodging the revenue sharing pool, it's a winning proposition.

Who knows what the Cards were thinking, but it's something to consider.  Naturally, the fans get the short end of the stick, like they always do -- like here in Oakland, where they've closed off the upper deck to create an artificial shortage of tickets to boost prices.  But, you know, MLB isn't really about the fans.

deal back at Qualcomm when they were terrible, cutting the 70K to under 40K. Personally, I thought it to be a good idea. NA-C in Oakland and the Q in SD both suffered from the same fate -- expanded for football, leaving acres and acres of empty seats for baseball, which were filled maybe, twice a year.
The Oakland situation is even more ugly, because the remodel job was just patched on the the facility, with total disregard for how it looked. (Mt. Davis?)
At least the expanded Qualcomm was done in harmony with the original structure. Obviously, the A's are in dire need of a baseball park -- but will it happen?

Regarding the baseball-only cable channels....if the team can pull it off, more power to them. The Padres have their own channel through Cox Communications. The Tribe has just broken away from FSN Ohio. The Yankees are the prototype, with YES. Radio's a different business model than a cable channel, though. If you want to start a channel -- well, way to go. You just have to make sure all of the market's cable systems sign on to the proposition and feel that it's going to be a winner for them. But -- to buy an over-the-air station - you've got to go through the regulatory channels....and they were not going to buy a legitimate St. Louis signal, it would cost WAY too much. I suspect the 'birds will find owning a radio station to be a losing proposition, overall, and not the pot'o gold they thought it would be. My guess is -- after a couple of years, they will will sell KTRS and find their way back to another St. Louis frequency, be it KMOX or another station. You really can't value your advertising inventory very highly if much of the market -- can't even hear it.