That's so lovely. I think it totally depends on the guy. I have several guy friends (early to mid-40s) who do things like this (pull out chairs to help seat their dates, hold doors, hold coats, make sure they walk closest to the road). Their dads do, too, and they're teaching their sons to do the same. Then I have other friends, who while great friends and doting on their partners in other ways, just never think of stuff like that.
I hope I'm showing DS that being a gentleman is a way to show he cares, too, or in the case of strangers, is a way to be polite. I know he sees my dad, Grandpa, hold the door for or help Grandma out of the car. And I think it's sinking in. DS may not always remember to hold the door for me (it's so hard to slow down all the time
), but if there others walking out of or into the building, he always remembers to hold the door. And to be honest he's tried to walk closest to the street with me, but it's awfully hard for me let him; at 11 yo, he may be as tall as I am now, but it's hard for me to not think of him as little still.