but look how many keyboards throughout the nineties came with a bigass enter to please people who were into the AT layout.
Or with F keys on the left.
many professionals kept *****ing about the 101-key layout and how it was so much worse than the AT layout and that typists were forced to buy alternative keyboards so that they didn't have to use the "unusable" Model M's layout.
Bigass Enter lingered longer than any of the other errata. For one thing, it (along with ISO-style Enter) seemed more natural to people coming in from electric typewriters (my generation).
F keys on the left was the big thing, when my original 1986 keyboard went bad in the early 1990s, I had to shop hard to find a replacement with F keys on the left. Unfortunately, I don't remember what models either of those were, which is good, because I might be kicking myself today if I did. The idea of buying a used keyboard never crossed my mind, if there was even such a market.
Those "typists" you mention were early adapters who had been through the XT and AT lines and become accustomed to them.
Standard Model M layout (excluding the numpad) is probably closer to an electric keyboard that AT or especially XT.