The point about being a non-Catholic religion is that those who go that route don’t see where Catholics have the authority to restrict the use of a name–like ‘Bishop’ or even “Christian” to themselves.
Personally, I don’t think the man is a Bishop either–but then, as a Mormon, I don’t think that Catholic bishops are actually, y’know, bishops with priesthood authority. If I did, I’d BE Catholic.
To rope this thing back on topic…remember: whether this man is guilty of these offenses or not, it reflects on him, not on Christianity as a whole; in fact, in a very real way it says good things about Christianity in general.
For the same reason the saying is 'wolf in sheep’s clothing," not “wolf in a lionskin.” Preditors go where the prey is, and hide among the innocent. Child molesters become ministers, teachers and scoutmasters; not because these professions are full of their own–but because they are not. Because the vast majority of them are trustworthy and good men and women who are doing what they do to help others, sexual preditors find easy access to their targets, like a hunter in a duck blind.
After all, isn’t that why finding such incidents is a scandal and front page news? Because it is unusual and wrong? What is that old journalism saying…“Dog bites man” isn’t news. “Man bites dog” is.