That's true, but it's often equally true that the supervisors making the decision are too lazy or unimaginative to initiate the pay raise. The threat of leaving the company isn't only a bargaining chip, sometimes it's the only opportunity. I've even seen people achieve big salary gains by yo-yoing between two companies over a relatively short period of time.

Yea, from my perspective the "company man" doesn't exist anymore for the most part. There are people who buy into the cool-aid, but most people treat the company they're with with the same loyalty it treats them: almost none. When a better opportunity comes along they tend to jump. I can't recall more than one or two cases where the person announced they were leaving and got a counter offer good enough to make them stay.