Huh? Those were totally different scenarios. Alan Wake was initially coming to both Xbox 360 and PC (think it was supposed to require Vista or something) but eventually the PC version was cancelled.

So obviously people that wanted the game on PC were disappointed. If they wanted to play the game on their PC, they couldn't. They would need to have an Xbox 360 to play the game and some PC players do not have any consoles so buying a console for a single title isn't all that appealing.

Obviously Alan Wake ended up coming to PC eventually but it was much, much later. Almost 2 years after the Xbox 360 release.

In Quantum Break's case the game was initially marketed as Xbox One game, no news about possible PC version. So it was assumably an Xbox One exclusive title.

Well quite recently it was announced that the game would be available on PC too. How does this affect the players that want to play the game on their Xbox One? It doesn't. At all. They can still do that.

Of course if people bought Xbox One only because of this game and would have otherwise simply bought the game on PC well those people may be disappointed but perhaps they should have waited a bit more in that case. But overall having MORE platform options is not a bad thing unless it affects the other platform versions in a significant manner.

The other negative stuff surrounding the PC version of Quantum Break is mostly about technical stuff and that's hardly surprising and I doubt people are actually surprised to see negative opinions about some of that stuff.

TL;DR Alan Wake's PC release was cancelled, PC players couldn't play the game until much later when the PC version was eventually made. Quantum Break's PC version doesn't take away from Xbox One players, it simply makes it possible for PC players to play the game too. Different scenarios, different reasons to complain.