Yeah, if a whole bunch of them decided to do something else instead, there would be no dire consequences. If a whole bunch of them were forced to on the other hand...say, because their signal went blank during a switchover...well gee, what could possibly go wrong?
Aside from general anger at the situation, we have:
$116 BILLION (46.3 BIL in the US alone) in revenue generated from Television Advertising in 2007 alone (the most recent report I could get with a quick google search, though you can be sure that number only goes UP each year). I'm sure our economy could handle losing that money without ANY problem whatsoever.
Numerous jobs, all the way from grips to production assistant to program manager to the more illustrious positions of each show on television. Let's not forget maintenance positions, linemen, customer service...I can't find any numbers on this, but I'm sure you could imagine, it ain't a small number.
How about the cultural impact? Say what you will about the value of television as a cultural export, but the fact remains that part of our culture today is the result of shows from yesteryear. Additionally, a decent amount of money changes hands just exporting this cultural medium between countries.
That's only a few examples I could come up with after waking up from 2 hours of sleep- if I were more awake, I'm sure I could come up with more. Either way, it seems you have a very subjective opinion on what is and isn't important.
It's not important that people watch tv for the content, but the world has adapted to television, and relies on it at the very least from an economic standpoint- this is true whether you agree with it or not, whether you think it SHOULD be that way or not, and whether you WANT it to be that way or not.
Yes, in this case the popularity of the medium has has made it important.