I know there are a lot of people like this, but there is also a perhaps equally-large number of people who feel the opposite way. Personally, I love to be proven wrong when I predict failure, unless I have some other reason for wanting someone to fail (they use unethical practices, they're my direct competition, etc.).
I think this is really why you don't have to worry about competitors. If your idea is good enough, everyone will think you are crazy/naive. If your idea is simply decent, you'll never pick it anyway (because it's not exciting enough to you) and it will end up getting done by some existing company. Either way whatever you actually choose to work on will be unique until it's proven, by which point no competitor is catching you anyway.
It's not just about feeling. If Google had tanked, you would be more justified (in a statistical sense) to think that you're smart and to engage into more financial transaction.
For example, I was just over on programming.reddit.com. The majority of the comments on this essay are smearing Paul's character. If you went by that, everyone hates it.
Yet the essay has +115 points. So there are 115 people who liked the essay for each person who dislikes it. Where are their comments?