If the checkmate is obvious then there is no real reason to play it out. You might see it as denying your opponent satisfaction but most will see it as wasting their time. If you watch long games with very high rated players, they resign games as soon as they see they can't win, even if checkmate is still out of sight. Us mortals can always hope our opponent will make a mistake but if it's something obvious or forced then there's no point.
Also forcing a stalemate is not considered rude and yes you are right, it's very much an integral part of the game, for forcing a stalemate or repetition of moves. Some people just like to whine and complain.
I’d like to get your thoughts on resignation. I’m fairly new to the game, but in my opinion, resigning is a bit of a cop out - aren’t you denying the opponent the satisfaction of a checkmate?
Also, when it comes to stalemate, why is it considered rude to force a stalemate instead of resigning? If your opponent can’t checkmate you, then that’s their problem and they haven’t been able to win right?
Posted this as I wish to be enlightened. :)
Kane