C'mon, football survives at a lot of places that don't get any TV money. They play football at Yale and Northern Colorado, they play at Maine and Montana. They don't get on TV often, but fans go to the games, coaches get paid, some players get scholarships.
Bowl Division Football is a hugely expensive endeavor--85 scholarships, highly paid coaches, facilities, trainers, travel, etc. To pay for it, you must put butts in the seats. Even if CU ends up with a cool $25 million a year from the conference payout, it will pay for less than half the AD's budget. The bottom line is that several (many?) football programs now competing in the top level cannot afford it . . . so play at a level below. You won't be on ESPN very often, your smack talk on the internet and at the water cooler will be weak, but you can still go the games, root for your team, and eat a hot dog.