Religion is not a "private pursuit"

We do not live in isolation.

The slightest thought of the manifestly intelligent person should help us realise that religion is not a personal or private pursuit. 
I mean religion is essentially a community activity, it's about relationships, family life, society....etc and etc.

It's a big call to question the Pope's right to make observations about outrageous things that people say from a religious perspective.

Let's face it, Trump doesn't seem to have any qualms about questioning the Pope or  anyone's bona fides on anything. Certainly  he doesn't seem to think there are any limitations on his right to comment on things that he is manifestly not qualified to coment about.

As for the furphy that religion is private and leaders should not offer political critique, try telling that to Mary...who saw her son crucified. 
Or to Mohammad, peace be upon him, who never felt such compunction. Or to George Bush who blatantly exploited his evangelical credentials.

Or to Barack Obama who sang with true faith of God's Amazing Grace. (https://www.youtube.com/watch?v=IN05jVNBs64)