(Quick recap, since there are now replies - EA had a policy of owning everything you produce, including the off hours, and with their constant "crunch mode" they expected you to not have time for any pet projects to begin with. An inherently abusive company, and very brazen at that. It was like that when I interviewed with them several years ago, but I doubt things changed much.)
Even a game that directly led to my employment at one of the companies, as they saw my game showcased at a game convention when it was a finalist in a major game competition, saw I was local, and brought me in to discuss a possible publishing deal (which turned into a job interview).
As someone who had made and released about 8 small games on my own and liked doing it as a break from my other things, it really rubbed me the wrong way, and I didn't end up releasing that game until after I was no longer working for the company and I had lost all benefit of the free marketing I had from the contest.
It's part of the reason why I haven't gone back into the game industry since I got out. I don't want to feel like I can't make anything on my own again (especially now that I'm getting into board game design and getting game designs signed with board game publishers).
My current employer's business has nothing to do with anything related to gaming whatsoever, so even if they did try to take control of my games, they'd have a hell of a time taking me to court over it, or acting like I violated any noncompete laws.
As to crunch most teams I worked for at EA did not crunch in the sense you're suggesting. There was widespread recognition within the company that long term crunch was both deleterious to productivity and morale. Studios were increasingly adopting a system called "focus mode" - a short period of focused work towards a specific goal (milestone/demo/etc) where non-essential meetings were cancelled, lunch catered, and distractions eliminated - which purported to produce better results without more than standard hours.
Studios at EA are fairly free to operate autonomously and they each have different cultures. Some were slower to adopt better practices around crunch, and even within the same team some disciplines would often crunch while others worked normal hours. Still, there was recognition of what better looked like in terms of production and will at all levels to make it happen. Not what I would call an "inherently abusive company".
After acquisiton, key people start leaving the studio, games released end up being rushed/crappy, and in the end they are closed.
Bullfrog, Maxis, Westwood, Origin to cite the more known ones, too many to be a coincidence.
As of now, I wouldn't be sitting comfortably if I were working at Bioware .
In many cases the studios were acquired because they were in financial straits and wouldn't have survived otherwise. Key people leaving after an acquisition isn't surprising: your studio was acquired because it made X type of game or franchise and maybe you don't want to continue doing that; your retention stock vested, time to try something new; you're entrepreneurial at heart and want to start a studio again after a (successful) exit.
Maxis and Westwood (EA LA) went on to make their most successful titles and decade plus runs as EA studios. Likewise DICE, Bioware, Tiburon, Pogo.com and several mobile studios.
Take for example BioWare, they were acquired 3 years before their best game release: ME2 then they released ME3 an other excellent game then ...
It doesn't matter the unidirectional power assymetry. It doesn't matter if the contract is unconscionable. If you want the job, you sign the contract. And even if its illegal good luck going thru the courts to litigate. The companies also have more money and can outspent than you have to live.