Indeed I agree, I do actually see the benefits as well. If you get caught you wouldn't have to worry about getting thrown in jail, having your animals taken from you, and you could let your vet know that you're a sexual couple so that if something arises and you're in a compromised position you don't have to worry about getting exposed... those are all valid reasons to want legal protection.
But it wouldn't stop the social stigma, nor would it stop people making you into a pariah if caught, nor would it stop your friends and family from potentially abandoning you if they found out, nor would it stop someone from trying to dox your information no matter how legal it is. But the point is moot. Legalization or even decriminalization pretty much have the same odds as a snowball in hell. *We* know that animals can and do have the capability to consent to and enjoy sex. But we're up again a 10,000 foot wall of human ignorance, and unfortunately human ignorance in this particular matter will likely never be corrected.