[WorldMaker]

Space Cadet (Pinball) has the most direct answer: it was written largely in x86 assembler and didn't survive a 64-bit translation attempt. Raymond Chen says the ball would ghost off the table, fall down and end the game in seconds when trying to run in 64-bit math. Raymond even takes personal responsibility for the failure to keep Space Cadet alive and disappointment it didn't survive past Windows XP:

https://web.archive.org/web/20160205141748/https://blogs.msd...

The larger answer to the rest of the games seems to be related: Windows trying to shrink its non-cross platform code "liabilities" and things it needed to translate between processor architectures. The games were never a priority for the Windows team. Most were either intern projects and/or contracted from "second party vendors". In Windows 8, Microsoft decided to completely contract all of the games to a second party, the strange and sometimes controversial Arkadium [1]. The Arkadium Solitaire and Minesweeper were installed by default for a while, but as Arkadium started injecting more ads and also quickly increasing the install sizes of the games, Microsoft did the natural thing and removed them as default installs so people would stop complaining about their size and/or ads and instead just adding shortcuts to install them from the Store.

[1] https://en.wikipedia.org/wiki/Arkadium