When talking about "exits", it might also be useful to keep in mind the amount of money you could've made while working a regular in the same period of time.
Of course I'll be the first to admit that working on your own projects is much more fulfilling and interesting, but it does have opportunity costs just like everything else.
Definitely - although it's also worthwhile to take into account the fact that you own what you produce when you work for yourself. So while after working for someone else for 6 months I would only have cash to show for it, after working for myself (very part time) for 6 months I had the option to turn what I produced into immediate cash, or do anything else with it that I wanted.
But I definitely agree that it's something to consider.
Of course I'll be the first to admit that working on your own projects is much more fulfilling and interesting, but it does have opportunity costs just like everything else.