I think it is far from being as simple as that. If one's ambition is to have better eyebrows, at best it makes you better in that regard, but quite likely says little if anything good about you. To take it a bit further, if someone has the drive/desire/ambition to be a better contract killer, I think we can keep them at the back of the pack.

I've met plenty of entrepreneurs whose desire to "do better" means, to them, a willingness to violate ethical, moral, and even legal principles that society holds quite dear. The valley isn't that different from Hollywood in this regard. It doesn't mean you can't find some outstanding people amongst entrepreneurs, because you absolutely can, but you can encounter some of the most horrible wretches known to man as well.