For some of the history of that time, I suggest checking out "Masters of Doom : how two guys created an empire and transformed pop culture", by David Kushner. The book is 15 years old (!!!) at this point, but I think it's still a compelling read.
Certainly strange to watch the definition shift over time.
In any case, the main thing I want to say is that it doesn't really matter whether they are 'in the trenches.' You are in different realms of existence if you own the company vs. work for it. As a founder, it's your personal creation; as an employee, you may care about the product, but the primary thing is your paycheck (most startup employees I've spoken with are much more mercenary with this than myself, too). You know that if it succeeds, the founder will become rich and famous and enter a social stratum that the employees will still only be able to fantasize about. No one will know their name or grant them ridiculous amounts of respect etc.
Even if none of that comes to fruition, the fact that your potential courses (as they relate to the company) are so divided creates immediate present-term social distance. And you lose the sense of shared struggle—or it's at least on a much lower level.
If you're all equal owners, the feeling of going to work on your shared thing must be very different, I imagine. I think it's probably also necessary to not take investment (or somehow do it in a very low pressure way), in order to have fun like the Id guys.
Thinking about how much Carmack has been up to since that book was written is super cool.
http://www.shacknews.com/article/101156/rocket-jump-quake-an...
I grew up in this era so I'm certainly enamored by the nostalgia trip but I have a lot of respect for the team at id, it's fascinating to read about all of the mundane aspects of ray tracing and compressing color palettes enough such that a game like Doom or Quake could actually work. id probably did more than any other company at the time to make programming seem like an alternative subculture instead of a science and to make games these dark and moody experiences that were a blast to play (especially with friends via LAN).