If your point was that people at the time were less likely to engage in sex outside marriage and that's why Steve wouldn't... No. I don't think you have a point. As noted all the people that Steve fought alongside in WWII also born when he was? Many, many, MANY had sex with someone in course of their tours of duty. They were all products of the same culture as Steve.
Look... It's obvious to some it's just somehow sanctifying to think that Steve Rogers never got some. Point blank I think that's just silly. And I don't think it sullies him as a character that he would actually have sex outside of a "true love" scenario. And I don't think it's reasonable given that yeah, I think the moment I mentioned before in TFA indicated Steve became aware of his sexual desirability and took advantage of that at some point. Saying he didn't have time for sex, again... SEX, not a full blown romantic entanglement with marriage as the endgame, is obtuse and doesn't match the reality of the situation of the war. In the modern age... Yeah, I think he never did find the time to be with someone, but even then... I am betting he and Sharon gave into desire at some point during his time underground. Once more... This isn't some kind of negative mark on his character we're talking about. He's Capt. America, not a Catholic Priest.