OK, I'm not all the way through this thread but for what it's worth (nowt!) I'll add my input.
Are people really that shallow that it matters whom the criticism is off? As already been said, photography is subjective and you don't have to be a photography god to be able to comment or criticise. OK, so we shouldn't post up the obvious shots with photo bombers or lampsosts in the middle of the car types, they're not really 'best' shots that you want critique on anyway.
All memebers should be encouraged to post comments, and as again has been said the 'nice shot' is acceptable as long as it is qualified with why the viewer thinks it's nice.
I have only made a small handful of posts (5) with pics in for a couple of reasons:
1) I'm new here
2) I'm not that good. I know it, but I am here to learn and expand.
3) the In depth crit section scares me!
4) I don't get out anywhere near as much as I would like to or am able to.
When I have made these posts, I have had a little critique, but not a lot (between 0

and 5 responses)
That makes me think that a) I'm worse than I thought I was, b) nobody likes me
I've not posted that to get people to track all 5 down and throw comments my way but I start to feel that it's not worth bothering posting anything else up. I'm obviously just posting mediocre pics, I don't know how to make it better and I'm not getting any guidance or help.
I'd happily have someone (anyone) come up and say 'that's just average and you could have done.....' At least it points me in the right direction.
Maybe it's me that is taking this the wrong way and I ma expecting far too much from the community

I went out for a wander and managed to capture a Roe deer in a nice simple pic that to me was worth the effort and the couple of hours I'd spent out that night. 1 person commented to confirm it was a Roe which is good, as for the pic.... nothing
OK, a bit of a moan, a bit of a rant in a way. Regardless, this is the perspective of someone new to the site and not that experienced. There's some great people on here that do share, and I appreciate everyone's time is finite but some extra advice/comments to those posts with only 1 or 2 comments or by people who have 'new here' or 'getting comfy' wouldn't go amiss to make those people feel part of the community and to help them become better in what they do.
I say that all pics should be open to crit, some common sense from the poster to look at how long someone has been here to give an indicator on how 'harsh' to be, but is it not entirely obvious by the pictures someone is posting at what their level is?
Sorry, going on again, I'll leave it there for now
K