Although I understand the sentiment, there's a big distinction between critiques from agents or editors, in the form of a rejection letter, and critiques given by peers.
I agree. It is nice to receive the positive in a rejection letter, letting you know (if true) that the story was good but just not the right fit. There is no value in getting that letter back if it isn't true, however. Personally, I've only ever gotten anything of use to me from negative critiques. The ones that are full of praise are nice, I suppose (if they're true), but they're not much use.

Myth Weaver