As someone who does a fair bit of vegan outreach learning how to talk to omnivores and vegetarians about veganism is always a learning process for me. You have to completely know yourself, your own position, and then try as best as possible to figure out the person you're talking to. So many things can go wrong. You can spend ten minutes talking to someone about how cows are treated in factory farms, only to find out that they prioritize protein over suffering because they 'work out'. Activism turns into a game where you're trying to figure out a stranger completely in under two minutes. In fact it sounds a little hostile and manipulative, which really isn't veganism at all. Lately I've been thinking - what is the alternative?
According to the vegan wiki the first principle of vegan abolitionism is that the animal rights position states that all animals have the right to not be treated as the property of others. I've always toyed with abolitionism and deeply respected it. As for the principles I follow 5/6 but don't call myself an abolitionist because I don't want to sully their movement (like many people do to veganism in general). So then let's consider abolitionism (or at least my understanding of it) and how that might make vegan activism a lot easier.
The first very basic idea is that no animal should ever be treated as property. That answers every question. Don't you need protein? No animal should ever be treated as property so I don't use animal protein. Don't cows need to give milk? No animal should ever be treated as property and when they are bought, sold, and then killed when they no longer produce optimum milk they are being treated as property.
Of course you may get some people who will disagree with the basic idea that animals should not be treated as property - but there is the division. I can't imagine a vegan who thinks it's okay to use animals like property, so this person will never be vegan anyways and there's no point playing the dance to figure them out. There are just too many cultural barriers in the way. Vegan abolitionists seem to accept that a lot easier than I do, a person that spends far too much time trying to find the best way to talk to every person. When you do that though you compromise your own beliefs. So often I find myself accidentally encouraging pescaterians, vegetarians, and sometimes omnivores. To encourage veganism to everyone you need to lower your own standards so that you can meet where they are at. In the end though you end up telling them it's okay to use animals as property - which I fundamentally think is a basic wrong.
So for now I'll try to answer every "why don't you do this" question with because it is a basic right for all animals not to be treated as property and see where it takes me.