Some might say "if you have nothing good to say, don't say it". I tend to agree, if I really have nothing constructive to suggest afterward. But I think it's more of a destructive habit knowing that no one likes to fix the boat, especially when sharks are around taking advantage of the situation.

On the contrary, if you have something to say, please say it no matter whether it can hurt. If its constructive, it will always be helpful at some degree.

And I fully agree with everything you said :)