In many ways, it is actually a very selfish decision on my part as an Engineer -- I'm doing it because i'm thrilled with my job, the product I work on (and launched) and cant stop thinking about some of the Engineering problems I encounter -- because they are so fascinating.

My current employer is shrewd in that they have aligned their interests to mine -- they have moved away most of the BS typical of engineering jobs. They have other people do the parts I don't enjoy doing, and they have given me wide latitude in Product and Product Engineering decisions. They have also given me wide latitude on task selection -- which tasks I take and which get assigned to others on my team (or others on other teams.) This isn't a constant state, it happens on several sprints a year.

On a side note, yes, I exert lots of creative energy in other domains. I'm on the board of a non-profit mentoring org, I'm an advisor to a nature conservancy organization, and I spend a huge amount of time with my family and children.

When I was single, I was part of a community food cooperative and several educational mentoring orgs. Now, the lions share of free time goes to children.

Side note -- if/when my employer turns into Initech and I'm filling out TPS Reports, you can be sure I'll be clocking out at 5pm.

You are making a lot of assumptions here. Not all companies are bad or will throw you away. Maybe they are friends or family with the owner? In that case, helping the company bleeds outside of just an economic decision.

I didn't use the term "bad". I said it was based in economics.

It's called a work/life balance. Work, and the related money are a means to being able to live in this society. And how we choose to use the money and power, is how we affect society. But running to work after everyone else "goes to sleep" doesn't appear as a healthy relationship.

And I know of nobody who said when they got old, "I wish I spent more time at work".

But you're making the assumption that "work/life balance" must happen at the daily level. I'm perfectly happy to work my ass off for a couple months and then take a month off. To me that's a far better balance than trying to fit it all within a day.