"Would you let someone who has never taken a picture in their life tell you one of your pictures is no good and you should have done it this way instead?"

Yes, of course I would. Other photographers might have better insight into technical stuff (could, perhaps, tell me that I would have been better off if I'd gelled my flash, for example), but the technical stuff is the smaller part of criticism. Photography is fundamentally about the communication of meaning, and anybody with the normal range of intellect, emotions, and experience, who chooses to be attentive, thoughtful, and articulate, can render valid criticism of the art of photography.

Even with the technical stuff, do you think a non-photographer can't see when a picture is too dark, or too blurry, or has a weird color cast? Of course they can.