If I get an extensive re-write, I tend to just skip over the whole critique the first time I see it. If someone changes most of what I wrote, well, I wrote it the way I did because I liked it like that.
But then I usually go back, because I'll probably find something useful. Like Norman, if I'm posting for critique, I know there are some flaws, and I'd like to hear opinions of others to identify, and quite possibly offer suggestions to correct, those flaws. (If I thought the whole thing was a flaw, I wouldn't post it.)
On the other hand, if someone says that a particular phrase or line doesn't work, then if they do suggest alternative wording, maybe I can see why. Or at least tell if they are getting the same thing out of it that I thought I put into it.
When I critique a poem, before I hit "Submit Reply" I read it over and ask myself if I were the poet, would I find the critique helpful? If not, Edit...Select All...Delete. And because poetry is so difficult to critique, this happens probably more times than not.