The cost of changing jobs is pretty high, in my assessment. I mean, perhaps not if you're young, single and mobile; but if you are married with kids in school, own a home and pay a mortgage, changing jobs is personally very disruptive.

And then you have to develop a working relationship with your new boss and employer, and your new colleagues; you have to learn new tools and platforms, which may make you much less productive for up to a year. And all of these learnings carry risk - for whatever reason, the new job might not work out, and you might have to move again, this time maybe with a shotgun to your head.

The employer-employee relationship isn't symmetrical, even if you are a superstar engineer. No company has ever relocated just because a superstar engineer decided he preferred a warmer climate. Basically, staff are fungible, employers are not.