As for historical vs non, not everyone plays only D&D... so if one's dissmissiveness of the concept is based upon the crazy that is D&D, realize that's your hangup for being stuck on D&D, not a flaw in those that like historical, semi-historical, or alternate-history games.
Pendragon is much more realistic than D&D in a great many ways... including combat lethality... and includes modeling the physical differences and societal learned skills differences in the core rules. (Women have a smaller size, and higher dex, and different starting skill levels, as well as several things they can do without losing glory that men lose glory for doing)
Who said anything about D&D? Which, by the way, is pretty much a non-standard in terms of realism; "more realistic than D&D" is like saying "safer than eating mercury".
Pendragon is an odd choice to bring out as a champion of History and Realism, since it's an RPG explicitly set
in a mythology. And not just a mythology, but a very modernist view of Arthurian myth that leaves out unpleasant bits that we 21st century gamers tend to find problematic -cf.
Le Morte d'Arthur. It's handwavy history and intended to evoke a particular set of feelings and play style. Realism does and will take a back seat to the spirit of the game and story.
But you're really making the point you're grumbling about, which is that outside of a handful of 'strictly accurate' RPGs, we're all picking and choosing how realistic we're going to be, and what "realistic" elements we care about vs. the ones that we discard. There's always that one guy who has no problem with Dumbo being a flying elephant, but can't get past him doing a
power dive when for the entire movie he's been portrayed as a
glider. Or, in game terms, the GM who is fine with a female PC hurling fireballs or overpowering seasoned mercenaries with a single backstab, but loses suspension of disbelief if she can be as strong as any man. And there's nothing wrong with that - it's a matter of preference, not of Game Law.
It does mean, though, that when a group says that they do X because they must rather than because they choose to, many people will notice the transparency and lack of respect in that fiction, and will seek fun elsewhere.