Mind boggling, how is one supposed to change jobs? A company pays good money to attract top talent, but they must forget best practices and experience they developed at their previous job. Experience and knowledge should be allowed to follow the employee.
I had the good fortune of getting some advice from a couple of veterans of the Dallas gamedev community: they can't take what you have in your head, your knowledge and skills.
That said, the anticompetitive behavior of large tech companies and small game companies and startups is really saddening to watch.
They want us bound to desks with golden chains, doomed forever to toil on their pet products.
The key to growing as an engineer and the development of a new technology in general is being able to "play"--being able to talk to other older, wiser, and/or crazier folks without fear of repercussion or reprisal, of being able to develop something which may or may not go anywhere.
You know, the sort of innovation that patents were supposed to protect.