R’ Zalman, I guess it’s the “weird” thing. If the bochur is by default reaching the door first it would just be weird for him to wait for her to open the door for him. No chivalry or mentchlechkeit issue.
Where I live there is a massive tznius problem–(i’m referring to the not yet observant), so I have my work cut out for me. But unfortunately when I come and visit the predominantly frum cities for a chasuna etc., it hurts to see our girls not take pride in tznius. I don’t necessarily fault them for it, just the metzius of yeridas ha’doros. It should be taken very seriously, because there is a problem, (as you pointed out) and it should be taught as a subject in and of itself, which I believe is something that is taking place in NY girls BY schools right now.