I don't know anything about Virgin or Pixar, so I don't and won't explain them at all. For that matter, I don't know anything about the Mac, Lisa, and Apple II team. I have heard that Apple will create ten prototypes from scratch before picking one, but this seems a little different from having ten different divisions doing the exact same thing. I would be surprised if the ten different prototypes were made by ten different VPs, but there's a lot I don't know about Apple.

It matters a great deal if a division fails precisely because most companies only have one of them. If the company had two, certainly one could fail - but often companies don't have the resources for two. Splitting the division into two equal parts often isn't practical - sometimes it takes five people to complete a job and the company only has money for five salaries. And for most functional divisions - human resources, marketing, product management, finance, etc. - I really don't understand how the company could have two parallel organizations operating simultaneously, even if they had the resources, without causing damage to and confusion in the company.

I get that you'd like things to work differently - but I can only tell you how they work currently, at every company I've ever been a part of. If you can persuade a company to hire you as the vice president of something without lengthy experience, that's terrific, and I wish you much success. But you asked why companies don't generally do this, and I've told you.