From the dawn of this site we have struggled with problems conflict arising from different viewpoints and comment discussions that often digress into little more than ad hominem attacks. Most of these arise from well meaning people wanting to contribute butting heads about the way that should be done.
There are those that would say that calling a spade a spade is in line with the be nice policy but very few times would those people attempt to argue that saying that it was helpful. The be nice policy would still be in place but in addition we would add the expectation that the poster attempt to be helpful.