I think the Bradley people are stuck in the 1960s and refuse to acknowledge that not everyone these days is married and having a baby. They refuse to get with the times and realize that their insistence on using this term offends people--at one point during our training Jay Hathaway tried to refer to "animal husbandry" as the reason behind the term. Whatever. The entire organization is so backwards I'm surprised they're still around.
I use moms and support persons in this current class. I have a few military moms in my class whose husbands are deployed so I don't need to remind them that "dad" won't be there for their birth...but their doulas will! In past classes everyone has been together, so I've used mom and dad.
I'm a Bradley educator and the "husband coached childbirth" thing annoys the living crap out of me! I changed it to "partner supported childbirth."