Third reason is that it's waaaaay too hard. Why would I want to make eating difficult for myself? The animals are still being killed whether you eat the meat or not. You have to read package labels ALL the time, cut out a lot of good snacks and treats, some of the fake meats are expensive, and it can be hard to get your proper nutrients without the use of pills.
Being a vegetarian is easier than a vegan, obviously but it's still pretty hard. It could get worse when you want to start a family. Vegetarian moms should NEVER force their kids to follow their lifestyle.
Sorry, how is being a vegan hard? I can think of around 40 different kinds of vegetables off the top of my head ( and I am sure there are many more available that I do not remember right now ), while meat is always the same thing made in different, disgusting ways.
Half a dozen kinds of fruit are available every season, not counting the exotic ones and those that are off-season, but still available ( which in my opinion, should not be consumed, but oh well ). Nothing has to be cooked, so how can preparing all of this be hard?
Also, your way of thinking really disturbs me "The animals are still being killed whether you eat the meat or not"... Has their life no value to you, at all?
Reading package labels to understand the contents of a product can only be of benefit, and not only to vegans but to anyone who cares even just a little about their health. How is being educated about what we eat a nuisance?
Lastly, pills are not needed, especially in a vegan diet where nutrients are most abundant.
Who needs vitamin D supplements when you can just go out and expose your skin to the sun?