I'm in the L.A. area and people want to crap their pants when I tell them to give me 150k.
1) Management in all but one job I've had invested nothing in training and helping new employees grow. My technical growth has come through personal projects and taking on extra work.
2) Promotion never offered anything like the salary increases a new job offered. The incentive to stay is not there.
I think employers massively overweight experience, particularly in a field that changes as fast as ours. Five years ago I was just as smart as I am now, maybe smarter - I didn't have 5 years' experience with tools X, Y and Z, but tools X and Y are already basically obsolete. But the market says I'm worth twice as much now as I was five years ago.
Also, there is the concept of social proof - which you may argue is a form of over-weighting experience, but that's an open ended question. If you have a track record of going to work for somebody else and achieving X, Y, Z goals there, you are perceived to be a safer choice than someone that in theory might be smarter than you, but that is lazy or otherwise unreliable, or with low communication skills, or a first class jerk. Not that you cannot hire this types if you go with someone more experienced, but from HR perspective, you are more of a "known quantity" once you have been around for a few years and built a track record for yourself.
I think you fail to see a fact, the same fact that was overlooked by all your former bosses actually.
Your 6-years-ago self was probably not worth half of what your current self is. Your ability to land each new job was built upon the foundations of higher skills and professional maturity you achieved on the previous job.
Ambitious, talented employees keep growing, positions are static by nature. Job hopping is the de-facto career path.