Interesting, do you think this is more true for a medium-long term investment? I mean if you can put a prototype together by yourself in 2 — 3 months, do you think its still worth doing?
Maybe the core issue here is not having clear deadlines and milestones for yourself?
I do agree though finding and working with good people in a startup or in a corporate job makes the marathon of creating things easier and more enjoyable. However with a startup you hopefully get to share in more of the success, now with your mates.