If you need to pump out a high volume of moderately creative trash, then working in factory conditions makes sense. If you need to foster actual creativity, if you have a desire to build things that touch people's lives and that people will talk about and be inspired from then perhaps less so. The caveat that real artists ship is still in effect of course.
When it comes to producing amazing work, quantity beats quality. That is, it's better to produce 100 things and throw away 99 than it is to sit around a perfect 1. In the end the quality will be higher. http://russelldavies.typepad.com/planning/2007/02/quantity_e...
How are Jobs' keynotes so well delivered? Repetition, iteration, practice, just like martial arts, makes perfect.