I know in-story characters are always complaining about Agnes' attitude but I hope that most of us contemporary viewers understand that she's just too protective. Sure, she's snobby and elitist against the New Money, but I think her treatment of Peggy shows how "real" she is when it matters.
also in a patriarchal misogynistic world she knows all to well how much a woman depends on a man financially and socially thus it is IMPERATIVE that she have a good one. Adventurers are the opposite of a man who would, honor, care and protect his wife and any children of the union. I liked that Rakes guy but Agnes was right. He jumped on the nicer boat as soon as it sailed in, there was never any love in his hear for any of the ladies. I like the show has a male gold-digger trope and how much worse that is than a female gold digger. He would not only steal the money but also the safety, dignity and agency of the spouse.
