It's clear that there are two different points of view here regarding whether to critique or not. My preference would be to keep it simple. One forum can handle both preferences if the person posting the song just says up front what type of feedback is welcome.

Maybe things like:

"No feedback necessary, because I doubt that I'll change it"

"tell me what works and what doesn't in this song "

"Constructive criticism welcome, but be kind"

"This song is as good as I know how to make it... what am I missing? How can I make it better?"

"I want total honesty... tear it up, pick it apart, report any and all flaws so I can learn how to avoid them in the future"

That way anyone who cares to comment can do so within the guidelines set by the OP, and nobody will ever get more than they asked for.

https://www.dropbox.com/sh/ey71h8ep047758h/AAC12jNM0Hz9Q8zsh5iDeqNHa?dl=0