Without making a claim against veganism/vegetarianism, you do realize that people have been killing their own animals and eating them for many years. I'd wager most of the people who work in factory farms still eat meat. You don't find a huge proportion of butchers going vegetarian/vegan. I don't think that evidence supports that seeing how your food is killed has any impact on most adults, although it can be traumatic for children. The meet your meat campaign was largely ineffective, whereas making vegetarianism/veganism easy to do has shown actual upticks in vegetarianism that seem to be self fulfilling cycles. People aren't generally monsters, but that doesn't mean they want to sacrifice if they don't have to. Make a product that competes with meat on price, taste, and texture and I think most people will choose the vegetarian option unless there's significant social pressure not to.