Personally, I still think it was. Pretty much everyone in the industry wanted Minecraft on their systems and its developer as a first party studio, so Microsoft were pretty savvy to snatch it up so quickly.
Kind of like their decision to buy Rare those years earlier...
It depends on what they do with it. Merchandise sales are likely leveling out, and while Minecraft remains popular, it's got to be nearing saturation point, if it's not basically already there. The question is what they'll do with it to further Mojang as a company and widen their game library.
I really hope they don't go the route of locking games down to just being Xbox and whatnot. I've never really understood exclusives like that. Besides Nintendo (Which doesn't really count because I grew up with it), I've yet to see a single exclusive game that has ever made me feel I HAD to buy a console for it, from either side. Nothing Microsoft could put out for the Xbox One would ever make me want to buy a $500 console just for that- all the exclusivity does is really just cost people sales... And I'd be really disappointed to see any future Minecraft products take that route.
