for a lot of people its an immediate response, and they don't think about it. For me, I don't say it unless I mean it, but that can even happen on landslide victories 21-3 or whatever. If the people still warded, communicated, organized ganks that came close, and genuinely refused to give up its still well played.
If each team-fight the winning team barely makes it out, yet the losing team is getting frustrated at the loss, it can still be well played (they didn't facecheck bushes and turret dive when behind etc).
Also a habit from playing soccer while growing up...every...damn...game