It also depends on where you are in the corporate machine. As someone else mentioned on HN once, perhaps Gates couldn't even move up in today's Microsoft, but he makes a pretty good CEO.

You wouldn't be working in a corporate environment generally for very long (often founders move on) and in any case, it isn't like you are a "regular" employee if you are really successful ;)

A lot of things are easy to bear when you know they are temporary - and you don't have the locked in feeling.