I agree that diet is a personal choice: omnivore, vegetarian, vegan, whatever. But, a blanket statement that "meat isn't healthy" is just plain ignorant. SOME meat isn't healthy, like the toxic stuff they sell in wholesale stores and most groceries. But, if man hasn't messed with it by injecting it with hormones, or feeding it GMO corn, meat is a vital, healthy part of an omnivore diet. Large quantities of meat, to the near exclusion of most veggies, isn't healthy, either.
Humans were created to be omnivores. All cultures, except Hindu, eat meat. Even the aboriginal ones. It's instinctual, just as grass is instinctual for cows and horses. But, the problem with the American diet is that most people go overboard, whether for fast and easy food, sugar, carbs or meat. Corporate food in ALL forms, is the basis of their diets, and is centered around meat.
Meat is a healthy part of every diet if limited to healthy, naturally produced meat and eaten in moderation. Americans have made it the centerpiece of every meal, serving large slabs with few veggies, when in most other cultures it's eaten in much smaller portions or treated as a condiment when cooked with veggies. As usual, we've gotten it backwards. So, some react in an equally extreme manner by saying meat is unhealthy and shunning it all together.
Balance is needed, and moderation, as always, is the key. Avoid black or white thinking ... live in the gray.