projection?

I went to a writers workshop this week in which the critiquers were going off on tangents about where the work should go. The group leader said enthusiastic critiquers project their ideas onto the work being critiqued and that was a good thing. I have mixed feelings about this... On the one hand, I guess new ideas are always good. On the other hand, I think it's up to the author to create.

This touches on a bigger issue of what exactly should critique be? I often find I disagree with folks about this. I think critiquers shouldn't address WHAT is said, they should address HOW it's said--if it is effective. And is it internally consistent? For example, if you want to write about a flower-bedecked unicorn made of pink spun sugar who's a serial killer, I say: Okay. How does the sugar keep from dissolving when all the blood spurts on it? :)

What do you think critique should be?