I don't "detest" them but I do find them odd and amusing. The ones I have in mind also come under the heading of suffering from CMS (competitive mummy syndrome).
For example, I know of a couple of aquaintances in mind that fall into that catagory: A few months ago, my daughter, my son and I attended a coffee morning. Another mother said, "there's Mrs X with her little girl Y". My daughter said, "oh goodie. I love Y". To which the mother replied, "but you don't know Y". I added, "I think my daughter means Y Z". In other words, child with same forname but different surname.
The mother paused and said, "oh I don't know who that is." I was gobsmacked and stood there with my mouth open like a goldfish!
Why? Because before the said child and family had moved to another area, that particular mother and child's family were all but living in each other's homes! Yet, 1 year on from the date in which the child's family had moved out, this mother had totally wiped them out from her memory. She might as well have never met them! Indeed, she claimed she never met them nor knew anything about them and even said to me, "I really don't know who you're talking about".
There's a Yorkshire saying, "there's nowt so queer as folk." Indeed.