As a game studio - a developer rather than a publisher - it's very much hand to mouth. You are paid by the publishers on delivery of milestones. Milestone reviews can sometimes be subjective. You're basically the lowest link in the food chain and can be subject to a publisher's whim, which can often be a bit random depending on your external producer. Keeping such a studio open in the long term is about chasing new contacts, and any gaps between contacts is expensive because you aren't generating any income, but are having to pay wages. One or two project cancellations can easily shutter an independent developer.

In some cases studio owners may simply want out, or they might legitimately see a sale as bringing stability to the studio... Or it might just be greed. But I think it's hard to say whether a studio would have a safer long term future being independent or being sold.

Making game is extremely risky gamble. Sometime studio can spend years working on one game and it might result in subpar sales due to element that's not in their control, like Spec Ops: The Line. Take Obsidian Entertainment for example, over the year we kept hearing how they're financially struggling despite created some of the best RPG, and Microsoft acquisition suppose to free them from this issue to some degree. Same with Tango Gameswork. Zenimax and to some extend Mojang is different case though.

Lot of game studio open and close, if Tango doesn't sold to Bethesda and in turn to Microsoft, it might already closed. Though on the flip side it also mean they're at the mercy of their parent company, it still undeniable that Microsoft is the one killed them in this case.

I know a guy that sold his studio to Microsoft personally. He's been living a very nice life now, quite a long time after the sale.

He took the gamble. Made the risks. Exposed himself financially. It paid off.

Like any small business, you hope for a payout. Most won't get one, so you take it when it comes.