Those idiots would be the French where the name comes from? Same root as 'cavalry' too.
No, I'm talking about the idiots and buffoons who developed various D&D classes and kits and subclasses around riding a several-hundred to a couple of thousand pound extremely large animal around in a game with DUNGEONS in it's name, and in which easily 95% of published adventures (and a large percentage of home adventures) involve 50%+ of the adventure (often 90%+ of the actually dangerous bits, too) being in places where aforementioned horse either straight-up can't fit, or can just about sort of fit, but is a massive logistical challenge and certainly can't be used properly.
A cavalier isn't just his horse, despite the linguistic roots in our language, but you could barely tell that from many of the iterations he has had in D&D, most of which only actually get used when a halfling arrives on a large dog to abuse the charge rules.
These people were the kind of designer who stuck with a concept, despite it being a fundamentally bad idea. There's a ton of that in 1E, 2E, and 3.XE (not that much in OD&D and RC D&D, I note, which is interesting). Terrible classes, PRCs and kits which are sorta-kinda true to a "concept", but just are basically unplayable. "Complete" books from 2E were totally amazing for this. Some nailed it, like Bard's handbook, where probably most kits were basically viable, but others, like Ranger's and Paladin's were chock full of hyper-specialized, utterly ill-conceived, mechanically ineffective kits which were all "stick with the concept and damn the torpedoes!", but in a bad way.
The Cleric and Thief have both moved on from the healbot and trapfinder niches to become fully contributing, interesting, classes, in and out of combat. The Fighter has gone from badly-needed front-line defense, damage-dealing, & aspiring feudal lord, to DPS.
I want to disagree with this Tony.
Problem is, I can't.
You're not wrong about the Fighter in 5E. In 4E, oddly, he was a beautiful, terrifying beast of a class. Definitely front-line defence and damage-dealing, and maybe some other surprises. In 3.XE? Well, he was kind of just totally and utterly rubbish and reliant on a generous DM handing out magic items. But back in 2E he was also front-line defence in his plate with his HPs and often some serious damage. Weapon specialization, even before Combat and Tactics, was pretty hardcore.