Keep spreading ideas people, but do it with people who fucking know how to make those ideas work.
So what if I register it and it takes off? If the author doesn't care, that's one thing--- but looking at his post, he seems to care, and why shouldn't he profit from the site?
If he earns a lot of money doing so, he would totally deserve it, since as you perfectly point it out, it is one thing to have an idea, it is an other to actually make it come true. And I believe money should go to the person who makes it come true.
Personnally, I would like such a website to exist. Whether it is me or someone else who creates it doesn't matter. I would benefit from it anyway, at least as a user.
Also, it would not just about ideas, but also about people. For instance, one could enter "Lady Gaga" or "Justin Bieber". I believe it could be fun.
PS: To tell the truth, I'd even prefer that someone else does it. I am that lazy