It sounds like we do not want general critiques in this forum. That's fine, I know of other places to get that. I assume the part we don't want is the subjective part, such as emotional impact.
But what about questions on a particular photo asking how to fix particular known problems that are more technical?
For example, I have a photo that I've been told has poor contrast. I might ask how to improve the contrast when setting up the shot. Would that be considered on-topic?