Since I've become a parent, I've noticed 5:00 has become more important to me. We put our kids down to bed around 8:00, so I only have a few hours of quality time with them each day.
Secondly, there are just things you won't learn on the job. And that doesn't mean it's a bad job. My new shiny is currently Haskell. I shouldn't get huffy if my work doesn't allow me to time to explore it. It'd be nice, but I'm not entitled to it. And further, it doesn't mean I should start hunting for a "better job". So in my opinion, 501ers are left with three alternatives:
1) They only learn/play/explore things that apply directly to their 9-5 job. Or are limited to whatever time their work allows for exploration.
2) They find a job that aligns with their interests.
3) They make an business case to the company to incorporate the technology. (However this is best done after you have a level of experience with it)
People could argue which of those are better. But if you're someone like me and like to play with a large number of technologies, sometimes removing the job out of the equation is much easier...and maybe even more fun.
... and I'm guessing that's the majority HN readers.
There's only 24 hours in a day, no more no less.