When non-vegans say “mind your own business, what I eat is my own private decision” they think they aren’t making an anti-vegan argument, they think they are just venting frustration about some vegan who annoyed them, but they are. Not only that, they think they are stating a true fact, but they aren’t. Dominant ideologies tend to be invisible like that. People think that if they are not conciously questioning the dominant point of view that they are being apolitical, but they are being just as political as the vegans who annoy them, supporting the dominant ideology with what they say and do, whether conciously or subconciously.
Try to stop plugging your ears and eyes and read this: when you pay for animal products, you are paying for sentient beings to be exploited and killed. Your choice to eat animal food when and if you have plant based alternatives is inherently affecting someone else, it is inherently not a private decision.
This might hurt your feelings to read this, but by that logic I could say “mind your own business, where I put my hands is my own private decision” if I use them to punch someone. I am sorry if that hurts your feelings, but the fact is that paying for animal products is inherently not a private matter that affects only you.
Now you might have other arguments that you think justify that decision, but it is factually incorrect to say it is a private decision, because if we accepted that logic, it would justify allowing people to kill and rape each other because what they do with their bodies is their own business, their own private decision. Your right to bodily autonomy ends where it infringes on somebody else’s bodily autonomy, right to life, right to not be exploited.
And in this society animals do not have the same basic rights to bodily autonomy, right to life and right not to be exploited as humans, but to morally justify that you would have to name the trait that justifies doing it to other animals but not to humans, such that if that trait were applicable to humans, it would justify doing it to humans as well.
It boils down to name the trait. It always does and it’s not a private decision.
And if you don’t want a vegan who didn’t say anything to you to “get in your business”, try not insisting to them again and again and again that your financial support of the animal products industry is a “private decision” when venting about what another vegan said to you. In fact, maybe find a non-vegan to vent to them about what an annoying vegan said to you. They won’t feel they have to shut up and hear your say “private decision tho” again and again without challenging it, otherwise they are “forcing themselves on you” when that’s what you are doing in far more severe ways to innocent sentient beings by financially supporting the animal products industry.