Noncompete agreements and who owns experience

In Massachusetts, the governor is proposing to ban noncompete agreements.  Go Deval!

My first experience with such agreements stretches back to 1996.  This tech company wanted to hire me, but one of their conditions was I sign a piece of paper stating that if I left the company I couldn't work for any other place doing similar work for a couple of years.  When I first read that I was thrown for a loop and almost turned down the offer.  But then I talked to a friend in law that said those things were hard to enforce - such docs were used more for scare tactics in the tech industry.

Why would a company want to use intimidation tactics to keep their employees from jumping ship?  I can understand not wanting someone to go to a competitor with trade secrets, but there are already some laws in place to prevent that.  But wouldn't a more positive solution be make working there too good to quit?  When I worked at Hewlett Packard in the late 90s they called it "golden handcuffs."  All the perks of working at HP just made it too depressing to leave for some other company.

Another thing that comes to mind is that the company using a noncompete agreement is being hypocritical about experience.  When they look to hire someone, they prize that person's experience in the industry.  But then they turn around and damn someone who wants to take the experience they've acquired to a different company.  That really irks me.  Any experience I've gained in the course of my job (writing programs, building test systems, going to conferences, etc.) is MINE.  The company pays me for the work I do, and they own the product of that work.  They do NOT own the knowledge that I've gained in the process.  That knowledge and experience I've gained by being a good engineer and deliberately learning new things.

On a related subject, you could always watch that bad Ben Affleck movie Paycheck.  Then again, maybe not.