Well the cost of broadcast sports is super high because that's the price they can demand. They demand more, and the cable companies have to pay it because who wants to be the cable provider without ESPN or Fox Sports? And then if you want sports on your cable plan, you're paying an extra $100/mo because you have to subscribe to them all so the cable companies can make a profit.

And then you get into the question of the quality of pro sports. Lots of people are unhappy with the NBA and their heavy focus on superstars. Ticket sales are down, and fewer people are watching it on TV as well. The NFL seems to be getting into controversy after controversy that's turning people off. If the players aren't behaving distastefully and if the teams aren't cheating, then there's the whole concussion fiasco playing out right now.

Not to mention a lot of these sports teams lean on non-profit status and taxpayer-funded stadiums. What would have happened if Detroit hadn't funded a replacement for the Silverdome? Taxpayers are getting a bit more wary of where their public funds are going.

None of these things will kill pro sports, but they do lower the value. And it's possible someday a cable company will drop high-priced sports and not suffer any consequences. When that day comes... well the bottom will drop right out of that market.