In one case, the niche audience was apparently "people who want to read things that sound like blog entries by 13 year old girls but who haven't discovered LiveJournal yet."

I don't crit work I see no hope for. That's my whole "one positive for every negative." I might do "four positives for five negatives" but if there are so many negatives they outweigh the positives, I don't think the piece is probably worth the crit. I mean, there is bad writing out there. We all know this.

And sometimes, the person critiquing you has no point at all and is terrible at giving crit. Which also happens. But you need to be able to step back and tell the difference between something you don't like, and bad crit. Again.