Professors are basically there to manage the process and haggle for funding. They tend to not be very hands-on with research for the simple reason that that's not their main job. They mostly delegate that to people in their team.
And you can only become a professor by doing post docs, landing some tenured position and then maybe they'll make you a professor somewhere. It's a long, uncertain process and the failure modes are basically ending up with a teaching position or being otherwise stuck in some faculty mostly not doing research. Nothing wrong with that. But not what I was after. And a lot of teachers in university are basically people that dropped out of the process somehow.
Anyway, the whole management thing had no appeal to me: I did not want to be a manager managing other people doing all the fun stuff (research) while basically dealing with a lot of bureaucratic shit. Not my idea of fun, at least.
So, I left. It was the only logical thing to do. I worked for Nokia Research for a while after that. But the career paths there weren't a whole lot different there. And the whole thing started imploding a bit after the iphone launch.
These days I do startups and a bit of consulting. Mostly as a CTO, and I'm very hands on which is just how I like it. Inevitably, there's a bit of management involved as well. But I like what I do.