There is a big differance between constructive critism and simply being spitefull or hurtfull.  It is possible to offer someone ways to improve their style in a polite and kind manner.  Courtesy costs nothing.

It is also, I think, important to remember that often hurt & anger can cause us to express ourselves in ways that might on the surface seem perhaps discourteous to our peers.   In such moment's of weakness and pain on the part of others compassion and understanding are important.

Everybody stumbles sometimes.  If one should fall, can another not extend a hand to pull them back up?

It is generally considered bad form to kick someone when they are already down.