Oh, for fuck sake, it has been established in science that decriminalizing prostitution would reduce HIV infection rates, so once again, deontological concepts of morality are a cancer.
Your "shock and outrage" notwithstanding (
hey, we're trying for respect here, right?), "established in science" is only the start (Frankly, you'd better bring something more to the table than just "in science" - as there are a ton of social, economic, medical, legal and practical concerns to take into account). At the global level, however, we have actual practical experience with decriminalization of sex work - it's worth a read:
Wiki: Decriminalizing Sex Work. Ultimately, not as rosy a picture as you attempt to paint. Futher reading:
some opposing thought.
But again, immaterial. The point is that prostitution is mostly illegal on a global level (hey, even despite all those benefits you mention). And - again - that's adults engaging in a consensual sexual arrangement. Once money comes into the picture, things change (like the drinking and driving example).
The laws used to criminalize and punish the practice of bestiality aren't necessarily attempting to legislate morality (really, they are), they are "protecting society." And there isn't a legislative body alive that is will address "our rights to privacy" when the issue is abominable in their eyes which puts society at risk. Witness: the law is cluttered with existing prohibitions of /all sorts/ that won't get erased (bestial practices among them). Who's going to stand up for zoo decriminalization when getting a blowjob is technically illegal?
And herein is the issue: so long as you follow prescribed and established guidelines, you can help birth, nurture, raise, clean, kill, process and eat animals. You simply can't have sex with them (or, for that matter, do any of the aforementioned for the purposes of sexual pleasure or arousal).
I applaud your passion, but - ultimately - I think you are barking up the wrong tree.