Sounds like the attention of those properties' users is worth more in some other metric than the maintenance/improvements cost in engineer time. I wonder what.
Minecraft drives actual profits on consoles - you have to subscribe to play with your friends. Some of these consoles (XBox) are even directly owned by MS.
Github is a massive piece in the developer ecosystem. It drives adoption of other MS products that can integrate with it, and generates a lot of goodwill towards MS.
LinkedIn, eh, that's probably the weakest property. On the other hand, it's massive in the enterprise space - again lots of goodwill, this time from "suits", and maybe some cool metrics about hiring.
