So, between the few hookups I have had in my past via Grindr and the relationships which I have had, I have found that bestiality is actually exceptionally common. With females, they tend to openly admit having already had the interest in it. With males, they tend to share a opaque interest in the pornography, whilst not having partaken themselves.
It is my belief that: Most people find the idea arousing, but due to its extremely taboo nature, they are timid, if not afraid, to admit its desirability to them. But once I bring it up, it is typically agreed upon, sans a few particular haters who have their own niche, insecure opinion on it.
In terms of my own (monogamous, M+M) relationship that I am in now, I was at first very apprehensive to mention it at first....and was so pleasantly surprised to find out that he was into it, as well! He states that he first had it breach his mind once it was mention, although not partook in, by a Grindr hookup once. It grew from there...
So, my takeaway: Most people find it arousing, are afraid to mention it due to its taboo nature, but are more than willing to get off on the idea.