@extomar: I think Notch just doesn't want the responsibility of owning/operating a company and all of the headaches that entails. It's not about selling off Minecraft, but everything associated with it.
I definitely get that sense from reading up on the responses. And I get the sense that Minecraft is starting to shift into a "mature state" where changing anything is met with resistance making the whole thing "generally unfun".
To be clear I don't fault Notch for selling. I am only wondering if Microsoft over paid or if they could have spent that money in better ways like revitalizing first parties to release several new games and IPs instead or spent a fraction acting as an indie producer. I feel that Microsoft isn't going to beat Sony let alone anyone else with a game studio that had one hit where instead they could bury Sony in an avalanche of games.