People don't care because when they hear nay-sayers predicting dystopian futures, they think things like 'that could never happen here' or 'that could never happen to me.' The reality is that I doubt very much that if you had polled Germans in the 1920's about whether they thought that the atrocities of WW2 could ever happen to them or in their country, they would say the same thing, 'not here' or "people wouldn't stand for it."
People that predict doom and gloom are often called crazy, but not always because they really are. Most of the time people don't want to think that the worst could happen even when reality paints a different picture. If I had published a paper in 2005 predicting that Wall Street would crumble due to highly-inflated real-estate and that the government would spend $700+ billion propping up banks that were 'too big to fail' I would have been called crazy and people would have ignored me stating that my concerns were 'unfounded.'
Please don't use "people don't care" as some sort of argument against someone's beliefs. I mean, if his blog post is getting up-voted enough on HN to reach the front page obviously enough people here care about it to discuss it, but for some reason you're trying to tell those people that they really don't share Doctorow's opinion and that they need to wake up to that fact.