Playing one DOS game. Not supporting a whole platform and the software developed for it with a multitude of stakeholders (consumers, game developers, game publishers), lots of contracts and responsibilities to be held against those contracts. Verifying if each game runs properly on the emulation layer or if there will be unforeseen bugs later in the game progression due to some weird combination of programming voodoo and the system.

I don't mean to say that given Microsoft's development power it's a massive achievement but it's an achievement and should be assessed objectively, not with snarky comments.