I think it's more of the fact that writing a proper refresher course would take actual, you know, research.
Man, I would rather have a Donna that was raised on Paradise Island, because it makes so much more sense for her character. I like the idea of Diana's little sister being like, "Diana left the island! Why can't I go too?" and running after her. Plus, the idea of the youngest Amazon immediately running so soon after they kinda-sorta start interacting with the Patriarch's World would be really interesting to see resonate within Themiscyra itself. Obviously the outside world would seem glamorous and exciting to a teenage girl who'd spent all her life on the same island and had only ever heard about boys second- or thirdhand and now her big sister is not only going to see all that stuff and more but is going to go off and spread peace and love and the Themiscyran Way and probably even get to fight monsters--well, who wouldn't empathize with that? If that were the case, her weird taste in love interests makes more sense--they're not Amazons. She'd want someone kind of immature and a little flawed but not so serious all the time, and definitely a lot of fun.