I keep reading nonsense about how people who side with Schiavo's parents want to turn America into a theocracy. That's a complete misreading of why this case has generated so much interest. Vast ideological principles are not behind the controversy so much as small idiosyncratic details.
In short, a lot of people smell a rat. Michael Schiavo's story strikes them as sounding fishy. This is all straight out of Evolutionary Psychology 101: humans supposedly come equipped with "cheater detection modules" that make us particularly interested in, and suspicious of, other people's motives.
Personally, if I had to bet, I would bet that the husband's motivations aren't terribly sinister. But I could be wrong.
And that, more than anything, is why this is a big story -- because it's a small story, a human scale story. Different people can identify with the various characters and are suspicious of the others.