Like naeva said comments by nonvegans are allowed. The rule doesn't explicitly preclude anyone who isn't vegan from engaging in conversation. What it does not allow is for bad faith comments, strawmen arguments (carnist rhetoric and the like), and those that are hostile to vegans (antivegans) to come here and as the OP would put it "meatsplain".

I remove comments that are advocating for animal abuse, carnist propaganda, speciesism, and those made by antivegans.

Discussions about veganism here are heavily skewed as vegans are outnumbered vastly and it tends to be a sensitive topic due to cognitive dissonance. This makes it so that actual discussion is very hard as it often gets overun by reactionary takes and hostility to empathy.

Pinning posts has not helped in the past as most people don't read it or refuse to listen to the message before commenting here.

I cannot speak for any other mod, being newly minted, but this is not a vegans only sub.

Respectful and contextually appropriate replies are welcome but replies specifically hostile or following standard, trivially disputed, rhetoric will be removed.

For example I would not remove a reply like "What is it that determines whether or not something or someone is ok to eat in your eyes?" but I would remove "don't you know grass screams when you cut it. You're just hypocritical!"

Basically if you're posting stuff to own the vegans, explain why vegans are wrong, or saying something against veganism that a trivial search or five minutes considering the opposite position would show as false or grossly distorted your comment will be removed.

EDIT:

Just to add on to what I said. I think most of us would actually love to be wrong, if someone had strong evidence. Going vegan isn't tremendously hard, but it is definitely harder than never thinking about food and eating/wearing/using whatever you feel like because the whim to do so takes you. Mostly it can be socially isolating, because regardless of how much empathy you might actually have for carnists (having been one yourself, there is no shame in having been indoctrinated) people will feel that you condemn them and consequently try to shame you. (there was some study about this but I'm struggling to remember the title).

If someone could show me evidence that idk dogs were mere reflex machines like Descartes maintained when he vivisected them I would chow down. It's not really a particularly comfortable position to feel like you're living in the middle of a holocaust and most of the people you love and respect are not only oblivious, but actively defend and relish it.

It's just incredibly tedious to deal with the same set of disingenuous excuses. Like the aforementioned plants feel pain thing, I have never in my life seen anyone actually protest something like mowing lawns. I have basically zero reason to believe that anyone who isn't a jain thinks this is true, and even then... what is it that animals eat and how does physics work?