Maybe “WASP” vanished from the discourse because it was only invented in 1964, always had an edge to it, and came to be felt by many to be downright derogatory. At least, so according to a 1996 WaPo article (though I feel like I was aware of the term before I was 14 years old), from which I quote:
"Without the work of E. Digby Baltzell, we might not know what to call George Bush, except Poppy.
"Baltzell invented the term “WASP.” Before the acronym first appeared in his 1964 book, ‘The Protestant Establishment: Aristocracy and Caste in America,’ one had to spell out White Anglo-Saxon Protestant. Although, having done so, you would have barely begun to communicate all that WASP had come to connote by the time of Baltzell’s death on Saturday, at age 80.
"‘The term took off,’ said Frank Furstenberg, a fellow sociologist at the University of Pennsylvania, where Baltzell carved an impressive career from studying the nation’s elite when colleagues were more likely to lavish attention on the downtrodden.
“‘He happened to capture a portrait of a social class and a social time and a social place, when the power of the upper class was giving way and was being shared with a larger and more diverse group of individuals,’ Furstenberg said. ‘And Digby very much believed in that ideal.’”
"An ebullient, well-born Episcopalian, Baltzell spent his career warning the nation’s traditional elites to bring down their barriers against minorities or face the obsolescence that, in many ways, has come to pass. If he hastened the process by naming the group for an insect, Baltzell always claimed it was accidental. His book included tables that did not leave enough room in the headings for those four words.
"‘It was easier to just fit WASP in there,’ he once explained.
“In the literal sense, the term was more than a little redundant. Anglo-Saxons are pretty much always white, and quite often Protestant. But this acronym was always less about the words than about their sound. Saying ‘White Anglo-Saxon Protestant’ is like reading a checklist; it implies pedigree, hierarchy. It implied order, one that ‘people like us’ saw as their role to maintain, from the top of the heap.”
Despite its apparent specificity, the “Anglo-Saxon” part (which became popular in the late 19th c.) would exclude virtually every person in America – or in Great Britain, for that matter – with predominately English ancestry, since the Angles and Saxons, if they ever had a genetic make-up very different from other groups in their vicinity, had already, for centuries before (say) 1619, been mixing it up with various Celtic and Nordic peoples – not to mention Huguenots (mostly from Normandy and southern France) who found their way to England and the tradesmen like glaziers, some of them recently Jewish and all of them more Protestant than was usually welcomed in England, whom Elizabeth I encouraged to immigrate from what we think of as southern Germany. Also, like the Pilgrims, many Huguenots had spent enough time in the Lowlands to marry people from what we call Holland and Belgium before they ventured to England and/or America. Even the Angles and Saxons – Germanic peoples – intermarried with Celts, Picts, and descendants of whomever the Roman empire had brought to Britannia.
“Anglo-Saxon” is a term of no value of any kind.