Obviously, many things in life are a question of compromise. Yeah, he saved 5 minutes. Can someone claim that the decision the maintainer made was not a mistake? I think I stated my arguments on this particular bug completely enough to cover your examples.
I don't use Ubuntu (mainly because of poor upgradability, but while testing I did give up Unity precisely because of Klipper), but should I get treated like the reporter, I'll just leave, and not necessarily to Debian. And guess what, Ditto is a better replacement to Klipper and works OK on all Windows versions I tried. And Lyx will accept my bug report and donations from Windows too. Same will stand for Pidgin, Marble, Okular and QtCreator etc.
I'll stop, and also apologise Harald Sitter that I chose his bug to exemplify what I consider a costly mistake. I'd also report the bug and link it from Launchpad, but I have no idea if it reproduces.