I think being vegetarian more than the health benefits also has benefits for the planet and other living things.
If you think about it, animals are very inefficient meat producers (e.g. most of the food energy goes to the brain), so it would just make sense to create the meat (e.g. muscles) in the lab more efficiently. When most people are vegetarian, companies will pursue this goal quicker and will throw in more capital for R&D. Therefore, vegetarianism is the way to go guys.