Maybe in another 5 years the pendulum will start swinging back from conservatism towards liberalism, culturally speaking.
Right now the youngest people seem to be the most anti-zoo. 10 years ago, anti-zoo wasn't even a thing, at least where activity involving female humans was concerned. There was way more transphobia and homophobia back then. That has now reduced to some degree so everyone needs to unify around hating a new out-group. Amazingly zoos are the targets. Being an out-group is not all bad though. Before people were either ignorant or interested. Now thanks to the antis everyone is becoming aware that sex with animals is an option whether or not they are interested!
Paradoxically, we have become more culturally conservative as a backlash in the liberalisation of certain laws and behaviours. People are now looking for someone to hate on right now precisely because there has been so much change. We're basically victims of the backlash against the whole LGBTQ+ thing, and developments in womens' sexual freedom due to the explosion in sex positivity and online dating etc. Give another 5 years for these things to bed down and be accepted and then maybe someone will start a debate on zoophilia.
What is hard to judge is whether the awareness of this lifestyle option is disappearing on balance or just changing. Hostility is less of a problem than total indifference. I think we have already reached the point where it is way harder for people who have this interest to find each other. The taboo level has been ratcheted up to make it harder to talk about IRL while online censorship is becoming a serious problem. 20 years ago the internet was still anonymous and I would say as many as 10% of genuine personal profiles on myspace, livejournal, deviant art and other social media indicated acceptance of bestiality. Credit card companies would process payments for beast porn websites. There was very little censorship. Even a couple of years ago you could talk freely about bestiality on reddit as long as you didn't post images.
I think the trigger for change, if it comes, will be when somebody famous comes out as a lover of animal sex. They will face a backlash and be persecuted or even prosecuted but it will get people thinking and talking and the absurdity of the current position may eventually be addressed in the public discourse.