For me, it was PG's essay that overwrote this idea, which I had been raised with -
http://www.paulgraham.com/wealth.html
In defense of the amazing people who raised me with the work/pay assumption, they lived most of their lives in the Soviet Union, where there weren't many options aside from working for money handed down from a higher power.
It's definitely not just in IT.
For the sake of argument, one could say that life/work separation is good, and that people who start startups are workaholics missing out on all of the interesting things in life.
When I quit, everyone asked where I'm going. When I said "I haven't worked it out yet" (as I was shaping a startup) people just couldn't process it... Half assumed I just didn't want to say.
For a lot of people I just said "I'm going travelling", because it was something they could process.