Well I think Dan's opinion is both important an interesting and upvotes will get it to the front page where it easily visible for the entire community. Is it wort 2.5k? I think not. In fact I don't think it's more valuable than a lot of 0.02$ posts that I've seen. However this is currently how the system works. Should you downvote to cancel the reward? That's up to you. Personally I believe in upvoting the right content, and not in downvoting to take someones money away. If Dan himself thinks the post is not work 2.5k he could do something himself about it I guess.