You know what's funny? I'm way better mannered than most of the people who call me a poor sport. I do things like show up to my match on time, and I don't go on the internet and complain about my opponent not deserving his win no matter how cheesy or lame the tactics they use against me. On the other hand, I have received all kinds of disrespect from people without ever being given a cursory apology.
If somebody wants to say, "this match is over, you have won, I concede, good game," they can quit out of the match. If they haven't done so, then I will not treat the match as if it's over.
As for the pausing thing, do you know what would happen if I had somebody in a grab, and they mashed and accidentally brushed the Start button on their last stock, and then I quit and said, "good game you're DQ'ed"? They would complain. There would be a bunch of talk about me not finishing the match properly, about not winning "legit," and not having the sportsmanship to continue and let the accident slide. So if you're going to pause and end the match, quit and forfeit for yourself. Otherwise I will treat it as such and keep playing.
Hell, that whole "pausing to interrupt the infinite and DQ your stock so you don't have to watch" is stupid anyhow. I don't respect it in the slightest. I understand the sentiment, but I don't agree with it. It's conceivable I would have screwed up that infinite and he would have broke out, managed to shine-gimp Nana, then outplayed my SoPo and won. Instead, he (and others in the past) just quit out the stock, as if to say, "I don't want to watch you beat me." I give my hardest in tournament play. I don't understand why the other guy gives up when he doesn't want to watch me win.
When people talk to me about sportsmanship in this game, I usually have a giggle-fit, because I'm one of the few people who tries to judge his own behavior by a consistent standard, rather than stretch my standards to fit my behavior. When I behave in a way that doesn't meet my standards, I have always apologized and owned up to it. But in spite of all the disrespect I've received from players in this community, I can't remember the last time somebody apologized to me for insulting and maligning me through their words or behavior.