I know far more vegetarians and vegans than you do and they are all better than when they ate meat, also physically better. And I know them far more than you and I also understand that far more than you do. That many examples. Not all, but some of them went through heavy cleaning process (and when you really go through cleaning process, there is no amount of food that it can help you and it can last years, but at least then that person can be said was tough when it needed to be tough), but they got through. You know Nick Diaz... probably the toughest person in all of UFC... I think he is a vegan.
Close minded? So you eating an animal when there is no need, is moral? You don't see eating animals as immoral, and you are saying about close minded? What can be more closed minded than seeing a murder not being a murder? Sorry, but that's pathetic. There cannot be more close minded as that. People just need to cleanse them self of those energies inside that were created from the first time we ate animals, bad habits... that's it. We are not geared naturally, but were consumed by ego, by bad habits and it's gearing us to do bad stuff and to blind us. We are not geared towards alchocol, but we still do it. Eating animal is a very very bad habbit and body has attached to meat.
Talking about cultures... look at the cultures of divine persons (Buddha, Jesus, Mohammad, Bruno Groening, Lahiri Mahasaya, Sri Yuktersvar, Srila Prabhupad etc...) who were all vegetarians. But it's easy to say... I don't believe they existed. Let such beings be examples, a real teachers, not modern ignorant world.
It's better to learn to respects such powerful beings than idiotic modern world.