We don't strictly need a lot of things. We could still get by living in mudhuts. We don't need to eat plants only either. I don't endorse cruelty at all. I actually make a minimum effort to not support it whenever possible. I'm saying it's a bad argument.
There are ethical ways of buying meat, eggs, etc, thus no need to be vegan or vegetarian. Your reasons for doing what you're doing are yours. Of course you can share them, but don't beat people over the head with some superiority complex, because that is silly.