While I was at Microsoft this summer I learned that the PM position has become highly sought after by MBAs from schools like Duke etc.
I still don't fully understand the PM role here at MSFT. At previous companies I was at, the nearest equivalent of a PM was involved closely with engineering to organize projects, discuss features, etc. Here, they're just in meetings all day and emailing each other rhetorical questions. Having attended many of those meetings, the value-add seems trivial to me.
Maybe their job is actually really demanding and I'm just way off the mark though. It also likely varies from team to team.
Programmers don't have a monopoly on being interested in technology, nor do they have a monopoly on positive contributions in it either.