I'm of the belief that if you can't articulate your criticism in a way that actually tries to teach me something, I will not listen to you.
Do not treat me like an idiot.
"Your work sucks" -- ok, why? Why does it suck? Is it the story? The panel arrangement? The flow? If you can't explain it even to a child, then save it. Echo chambers and bad feedback exists when people are unable to go beyond their own personal desires and see what the artists were going for. People ask for "harsh criticism", get garbage like "your story is disgusting", and think that's good. They think getting feedback on what was actually good is "bad feedback"
No -- it's not. If I know what I'm doing right, that's less work for me to do. I'm focusing on what I need to improve, and that means knowing what I did RIGHT as well. Good criticism will see what you're trying to go for, get something different, and tell you WHY they got something different.
If someone can't tell me WHY they got something different, why they're confused, or why they didn't like it, I will not listen. That's not me being stubborn. That's me knowing the difference between good and bad feedback. If you can't explain why, I can't improve. Simple as that.
This is also why I limit myself to certain people -- it's not for an echo chamber. It's because they are able to tell me where I went wrong, how I can improve, and what I need to do to do well. They have an idea for this stuff, and they have experience. Good feedback comes from people who know how to give feedback on what you did good and what you can improve on.