This is *not* (only) about prettyness

I disagree, and agree very much with Jef. We'll end up being in a pretty bad place if the default interpretation of something that can easily be interpreted as genuinely nice becomes sarcastic and dismissive.

I don't want to be in this place, it helps nobody.

I do want to be in a place where you can express being personally sorry when disagreeing over a technical issue without being mistaken for a sarcastic disk who just wants to pour some extra salt into the wound.

Being friendly is not a bad thing at all, in fact it's often missing in the discourse in Free software communities, and probably makes quite some people stay away, or leave, because they just don't possess the time and energy to put up with discouragement.

In KDE (and a few other communities I know of), this has even been codified in a code of conduct, read for example http://www.kde.org/code-of-conduct/ or, maybe more relevant here, Fedora's: http://fedoraproject.org/code-of-conduct (although the latter is not very clear on this assume-positive directive).