I have a hard time sympathizing with this. Our project gets a handful of these "beg bounty" things a year; usually they're repeats -- SPF and "clickjacking" are common ones, but we also get other ones. ("You're exposing people's usernames through this weird JSON thing!" "Yes, we're also exposing people's usernames in the 'by' line of the post itself. There's nothing in that JSON that's not also available by just doing plain web scraping."). If we see a new complaint we always look at it to see if it's something we actually care about.
If you're working with pictures and audio of kids, or have details of people's activities that they may not want made public (like their taste in "Adult Fanfic"), there's absolutely no excuse for not looking at each report, even if 95% of them are low-value.
EDIT: I mean of course the "Report and then ask for a bounty" kinds, not the "Give me the bounty and I'll tell you the bug" kinds.