IMO that's not a valid reason to ignore deep-seated fears of others.
Fear of other people based on disability is discrimination. I have zero fear of blind people.
Fear of other species is not immoral. I'm afraid of snakes and alligators, and I'm just as afraid, if not much MORE afraid, of dogs, and my fears are justified by both hard data as well as past trauma.
Dogs aren't even the same species. It's not immoral to be afraid of them and having PTSD because of negative interactions with a particular predatory canine species is very normal.
Hopefully service robots won't be very far into the future. I don't want to discriminate against blind people. But I really don't think there is a problem with not being okay around a particular set of non-human species (alligators, hornets, lions, coyotes, dogs, bears, mosquitoes, ...)
Don't avoid a direct, clear question by painting it as non-serious.