People should stop being ageist. If anything, sexual predators are of all ages. Especially these days when Internet allows any bored idiot unrestricted access to any number of children from the comfort of their homes.
It isn't about people being ageist. The fact of the matter is that if you look like a bit of a weirdo and you are and older guy people will look down on you and find you suspicious. It doesn't matter if you or I think it is fair or not.