Is it? Maybe not just as a hatemail filter, but someone who actually collates responses, tries to get the reason for criticism without getting into arguments, and tries to extract actionable ideas from overall internet response could be an interesting offer. Sounds almost like it could be uservoice.com's premium offer.
I agree - doesn't scale, but it's far from a bad idea. I've done it for someone who takes reviews very personally. I abstracted the useful criticism and didn't make mention of the petty stuff.
