> I can’t think of too many other professional jobs where the line between hobby and work blends, for so many of its workers.

I would argue that the majority of rank and file programmers are not coding outside of work.

Anecdotally, this is my perception as well- I'd say maybe 5% of the people I've worked with are the "finish software dev workday, then go home and jump right back on the computer" type. Personally, when I'm done my workday, the last thing I want to do is sit back down at a computer (with rare exceptions for inspiration spikes).