This is a strange piece of writing. On the one hand, it's telling you that burnout is real, and that you should be careful to avoid it. On the other hand, it sound an awful lot like "there are worse things in the world than sitting at a cushy desk for 10 hours a day, whiner." The latter seems to undermine the former.

One of the best jobs I've ever had was manual labor: I was a bellman for a hotel. My primary job responsibilities included lifting heavy luggage in 100-degree heat, being yelled at by cranky guests, and running around non-stop for 10-hour shifts. What made it great? I was almost completely autonomous, and I got paid a little bit of money every time I did some work. There was almost always a direct consequence when I did good work, and nobody told me how to do my job. (My boss didn't even work on the same shift!)

I've worked a lot of much more "comfortable" jobs since that time, and I've had a lot of time to think about why that luggage-monkey job was so much better than nearly all of the intellectual gigs I've held. So far, I think it boils down to a simple point: there's no worse tyranny than being told how to think. No matter how much luggage I lifted, I was always free with my thoughts. But when you work in an industry where your thoughts are your primary output, it's inevitable that someone (or something) will try to consume all of them. When that happens, you're on a path to burnout.