I feel that negative feedback is more DESTRUCTIVE than CONSTRUCTIVE and quickly becomes divisive.

If the commenter has credentials or experience then their advice is respected and heeded but they generally remain neutral and silent.

Musicians are a sensitive lot and easily offended. Personally, I resent unsolicited advice from anyone who is obviously less experienced than myself. That being said, I normally invite constructive criticism.

Tactful criticism requires the wisdom of Solomon and few of us qualify.