I agree with this.The only reason I'm scared of it ever becoming legal is because of how hard it would be to legally define when it is okay and not. Because of this, I'm afraid zoosadists would find a way to exploit the laws to get away with doing bad things.
There is always something appealing in the human brain that often has us wanting to do the things we probably shouldn't. There's an attraction in lots of non-sexual things that make us say "oh I'm gonna be bad" even if it's buying that one thing you know you shouldn't. On the flip side of that is those extreme assholes that ruin it. I don't even like that my primary fetish, Sadism, is even linked to zoosadists. I can't stand when abusers run around in the BDSM culture carrying any titles or labels, but that's what we're faced with, abusers who ruin stuff. So yeah, keep it unlawful, underground, and unnoticed. We will always wear the masks of the social norms just so we can have our desires, kinks and fetishes left unfettered.