Naturally, people generally are happy when they win a game, any game, not just League of Legends. It is also natural that one would be annoyed when they lost a game in League.
There are however, cases where you are frustrated when you win, or happy that you lost. Do you have any games of that sort? I could share some experiences of mine.
Even on ranked games, if we won our games just because one enemy on the team disconnected because of ragequitting, I personally do not enjoy that free win, as it proves nothing that I'm realistically climbing up the ladder. I'm more of a person who prefers to make "amazing plays that win the game for us" regardless of role, outsmart the opponent, punish them for their mistakes, bait them into making mistakes, those sort of things. The thrill of a 4v5 doesn't exist unless the enemy really gives their all, in which most of the time it's the opposite.
Likewise, defeats are enjoyable on two cases. One, where we know all of us tried our best and yet the opponent plays better than us. That's a defeat we can savour, to strive us to learn and be better. Two, where we know our side is already hopeless (3v5 with 2-11 for instance), but our opponent opens up and talks with us leisurely while we have a /dance battle near Baron. While the latter doesn't appear in ranked games, it's still something to cheer up from.
I suppose the other time someone is frustrated for winning is when they're a troll who intentionally feeds yet wins... Are there any other examples of "shoddy wins" and "wonderful losses"?