bjjkid – as a girl no longer in shidduchim but who was for a while and is now married to a Brisker – I wouldn’t have said no for a boy opening the door or I wouldn’t be married now 🙂
Many yeshivish boys do open the door, many yeshivish boys don’t. Some are told specifically to, some are told specifically not.
So I also wouldn’t have said no if a boy didn’t the door because chances are he’s just following what he was told, and not being impolite.
(and yes I have friends from BJJ too, and they felt/feel the same way)