Let's face it: Since BG2, or maybe KOTOR Bioware has (also) been about the sales. Because, yes they'd know that without sales, there won't be any money to make games anymore. Or pay the bills - or the devs. And that may indeed have been a big influence in deciding to sell(out) to EA. To make sure, they'd still have a company to run, and by they, I mean Ray and Greg.
And Ray and Greg, and the other leads in Bioware have definitely seen Troika, Origin, Interplay (Black Isle) and other companies go down. And why? Because the people at Troika and Origin etc. maybe didn't have that much of an understanding of the business side of things.
Today, to stay afloat in the (big) business industry of making games, you'll need to make (much) money. At least this is so for both Bioware and Bethesda games. The devs. behind and of the Witcher 1 and 2 does not necessarily have to do this. CD Project is both a dev. and a publisher, hence they can forego this, I find.
Others companies that can forego this requirement of selling many games are indie games like Basilisk Games (The Eschalon Games) and Jeff Vogel (spyderweb software) because they mainly make the games with very little resources.
Even an indie company like Radon Labs didn't make it; the company behind Drakensang went belly up. And why? Maybe not enough sales for Drakensang 1 or Drakensang 2: Am Fluss der Zeit (the river of time?)
I don't know why 12 million people have bought the Call of Duty games, nobody probably does to the full extent. But I might have a good idea why. Many young men from 16-21 will take to each other and tell each other of what a nice and excting game they've played. And naturally all their friends will buy it too. However, I'm sure most of them will play it only once or twice, some of them may also be playing it over the internet to stay in touch with their friends. But what does this matter to publisher or the devs. They've gotten their money...
Like EA and Bioware will do from millions and millions of people come March 8th (or March 11 in Europe) this year.