I don't get the need for ad-hominem here. Though I don't necessarily agree with your parent, it's a valid point of view, and does not require the speaker to be

I don't get the need for ad-hominem here. Though I don't necessarily agree with your parent, it's a valid point of view, and does not require the speaker to be vegetarian or not themselves. The argument reminds me a little of the religious morality argument that only humans are capable of allowing God into their life. Again, I am not making either such claim, just rejecting your negative reply.