Very interesting and well-argued; it covers some of the problems that I've had with 'Endeavour' (and other modern prequels set in this period). I have been a long-term Colin Dexter and 'Morse' fan who read some of the books before the original TV series, and also know Oxford sites from the series well - including some of the interiors , eg at Hertford College and inside the Bodleian. (I've enjoyed sitting to work by the spot in the Bodleian where Morse finds the gun hidden behind the books in the episode where an opera singer gets shot from the nearby window.)
The main problem is the inevitable one that the younger 'Morse' does not look that much like John Thaw did on TV shows in the 1970s, and you have to suspend disbelief on that one. But the inconsistency between the views of 'Endeavour's younger Morse on women and other matters and those of Morse in the early, 1980s episodes , eg on women, does seem to reflect a general attitude by many modern writers of TV shows set in the 1960s and 1970s that the hero/ heroine must seem to be socially 'enlightened' on such matters, so as not to put off modern audiences. It doesn't ring true in terms of accuracy, or on how the majority of people in such positions and from that sort of background would (and as I remember) did think in the 1970s - and can be compared to the modern TV 'look back in horror' shows where old clips of sexist or racist TV shows, then hugely popular, are shown to younger modern celebs and they gasp in shock at some of the attitudes!
Being more careful about a possible 'hit' to viewing figures rather than careful to be accurate is probably inevitable in a commercial inter-show ratings war situation, or for selling such shows abroad. But perhaps this problem should be admitted more openly and flagged up as one of the dilemmas of modern TV writing, or else a lot of younger viewers could get a false idea of how social attitudes have evolved quickly. Logically, this also affects pre-modern era costume drama too - and is for example a major problem in 'Downton Abbey', whose 1910s and 1920s upper class characters treat their servants a lot better than they would probably have done in real life. 'Upstairs Downstairs', covering the same time period and issues but made in 1971-5 (well within the lifetime of those taking part in these events), was more accurate as to social attitudes, and in 'DA' I noticed that the 'sympathetic' characters were far more tolerant of Lady Edith's ilegitimate child or under-butler Thomas' homosexuality than would have been likely in real life.