I was in an interview once and the prospective employer asked me what church I attend. I replied, "Catholic." He said, "Is that even Christian?" So, yeah, plenty of Americans have a skewed view of Catholicism.
As discrimination based on religion is illegal in most of the world, it’s also probably exposing the person asking and the company to a lot of potential legal risk. It’s a big no where I live and part of the things you are explicitly trained to never ask about.