Why should anyone watch any ...

Question: Why should anyone watch any of the new network sci-fi shows when their record of cancellation is so predictable? Why should I get myself involved in the plot and characters when there's a 90-percent certainty that the network(s) will dump any new show? And why do the networks continue to produce new shows of this sort if they don't intend to support them? I was a huge fan of Invasion and Surface. We Surface fans even dared to hope there would be more episodes when the last show stated it was the "season" finale, not the "series" finale. I and all of my friends are highly disgusted with network TV. The only reason Stargate SG-1 endured was because Showtime premiered it and stuck by it. Thanks for listening.
Answer: I'm guessing this is a retroactive question, because there are almost no new network series that play into the sci-fi/fantasy arena (NBC's Heroes is the most notable exception). If you're wondering why anyone last season bothered watching any of the networks' genre efforts, despite the foreknowledge that most, if not all, of them were probably doomed from the start, the answer is simple: Watching certain types of TV requires a leap of faith, and if the shows themselves are good, as Invasion certainly was — I also enjoyed CBS' Threshold for as long as it lasted — I'd still rather watch great storytelling, for whatever duration, than the alternative. I have no regrets about watching any failed series, sci-fi or otherwise, if I truly enjoyed it as I watched. But then, I tend to watch TV in the moment, not worrying so much about the endgame and fretting about matters, such as renewal and cancellation, that are out of my control. Just because I knew Everwood and Invasion weren't coming back didn't mean I was going to miss the finale.