Here's a version of an old axiom, which you should ponder.

Good, quick, cheap. Pick any two.

I, and many others, have chosen good + cheap, at the exclusion of "quick" (i.e. that the software would be "finished" quickly, not that it won't perform quickly). The same is true with the release cycles of certain operating systems and software. It's done when it's done. Not before. As a result, certain operating systems and software are of much higher quality than their competitors. (I'm not listing which ones because 1. it's (?:flame|troll)bait, and 2. it's quite off-topic.)