Although it seem impossible and I've never seen a case but it there anyone out there that donates to people who makes helpful comments?
I donate but not for helpful comments. It usually has to be something worthwhile--like software development, charity, or service. I think, though, with the price of Bitcoins rising everyday, people may be less inclined to donate any amount of BTC. In the past, no one though twice about give .01 or .02 or so, but now these small amounts actually have some real value.