"the idea that the girls at the school would be gagging for the young doctor is an old perv's fantasy rather than realistic. I really felt that they should have been pointing that out just as explicitly."
Yes and No. I recall there being an attitude that, if one was of dating age, age limits on who you might date largely depended on how good a catch the man was perceived to be. At 17, i was allowed to date a med student, in the US, he would have been 24 or 25. I (nor my friends) wouldn't be able to date men that age in general, but he was going to be a doctor! This was in 1982.
Back it up to a decade to when marrying well was even more expected the teenager gagging for a young doctor is even more likely. In 1961 when my aunt began college at 17, many women hoped to get their MRS degree as soon as possible. College seniors, law students and medical residents were top prey being almost employed, and if getting to know them brought you in contact with men another year or two older and actually employed, so much the better for your prospects.
So, depending on the girls in question, in the 1970s their thinking could have been on that continuum. Some girls would not have been interested in a young doctor as he would be too old. But others would be thinking that dating a MAN with a profession was their best plan.