This is not correct. Multiclassing and the capability of martial classes created more varied characters earlier in the game editions.
Mixing martial and caster classes doesn't give you a martial character that isn't a beatstick, it just gives you a caster who's not as much of a caster.
Rogues at one time were more focused on non-combat activities than combat in the very early editions. You did not play a rogue to do combat. You played a rogue to be super sneaky guy that stole things and scouted.
So it's questionable whether he's 'martial?' But, he was a non-caster, and he did lack profoundly in versatility. Where a caster could sneak about invisibly, use conjured creatures or TK or even knock to open doors and trigger traps - and also bust out combat spells, the rogue could sneak around (by succeeding at /both/ a hide in shadows /and/ a move silently check, both of which were pretty low) and make really pretty tough percentile checks to open locks or find & remove traps (separately), and suck in combat. Same lack of versatility as the unambiguously 'martial' fighter.
And, of course, the Ranger & Paladin, who could be regarded as martial, were also casters.
There is no logic involved. Applying logical arguments to a gamed based on traditional fantasy tropes mined from historical and literary sources is not a compelling argument for change.
How 'bout the fact that the game completely fails to capture said tropes? D&D casters, for instance, are wildly over-versatile and over-powered and have more consistent abilities than any of their sources of inspiration. In myth and legend, for instance, a magic-user - typically a villain - will be able to do one or a few supernatural things. Circe, for instance could change men into animals, and not really anything else. Merlin, Gandalf and the like didn't exactly run around throwing fireballs like a D&D mage, either.
For that matter, if you go to the nearest source of inspiration, Vance's Dying Earth, the magicians he imagined could cast only a handful of spells a day - even the greatest Vancian magicians ever alluded to in his works could manage to memorize at most 10 spells - something D&D wizards exceed while still in single-digit levels.
No, the only tradition that says casters must be wildly versatile and powerful while martial characters are choiceless beatsticks and inflexible specialists is the tradition of D&D, itself. A tradition that modern editions have tried to overcome with varying degrees of success.
There has been no prejudice towards martials.
There has been, and is. The hew and cry over martial characters in 4e finally getting close to rough parity - the edition war, itself - is clear evidence of it.
The problem with your viewpoint is it founded upon the idea that you should have the same options and agency as other classes. That your choice of class should not limit you in any fashion. That does not in any way imitate the source material the game is based on.
You're a little off - veering into straw man territory as you must to try to make the idea of balanced classes sound unreasonable or 'samey.' No, the idea is that any given class should have the same amount of agency, a similar array of choices, not the exact same choices. An old-school fighter had little more choice defined in the rules than attack or not. A caster of moderate level had a lot of spell choices. A more reasonable system would split the difference, given the caster only a handfull of spell choices, and the martial character a handful of maneuvers or tactical choices - similar in number, impact, and thus agency, but entirely different in kind.
You somehow want the game designers to create a fantasy game meant to attract fans of fantasy (not anime) that makes casters and martials equal in nearly every facet of the game, when this has not been the case in the very stories the fans read.
I guess this is worth repeating: the do-anything, dozen-slots-a-day, fire-and-forget-wizard does not exist in /any/ of the source material. Not even Vance. It's an artifact of D&D's failure to get the genre remotely right.
If your preference is for martials to have super powers like anime characters or superheroes, then find a game system that does that well. D&D is not that system, never has been that system, and probably never will be that system.
You insist on wandering off into strawman territory again, and pretending I want a superhero game, when, in fact, I'd just like a balanced game that is /closer/ to the sources of inspiration by having martial characters that actually matter
There have been rays of light here and there in D&D's history. For a few years, the game even presented reasonably balanced classes and brought martial characters closer to parity. During the playtest, there were a few packets that were going in promising directions. The game's philosophy has become more open to homebrewing and DM-empowerment, so a good DM can mod it to be less at odds with the genre it purports to emulate, and to give players afflicted with a preference for martial archetypes more & better choices both at chargen and in play.
Why a martial archetype? "Martial" only covers one pillar: it basically says that you want combat options that don't involve magic.
It's more evocative of the kind of non-spell-casting heroes that populate the fantasy genre than 'mundane' and not as clumsy as saying non-spell-casting-hero-typical-of-fantasy-genres.
D&D 5E supports that style okay but it could certainly do better: it would be cool to have options for "things you can do with weapons." AD&D handled this via called shots (e.g. targetting the enemy's weapon, or cutting his hand so he can't hold a weapon, or parrying his attack, etc.) and apparently 3E handled it via feats and prestige classes.
And 4e handled it extremely well with martial exploits that matched other classes' spells in power, effectiveness, and availability - if not quite in versatility - while being entirely distinct and still clearly non-magical.
D&D could add a detailed subsystem for social intrigue: everyone has a certain number of social goals, strengths and weaknesses, and Reputation resources to deploy, and over the course of several days gossiping/politicking you make Insight or Diplomacy checks to protect your Reputation and degrade (or enhance) others' and/or accomplish your social goals.
It certainly could. It might be better based on background than class. Class could handle the combat/adventuring aspects of a character, with manuevers, special abilities, and spells of classes focused on those things, exclusively. Backgrounds could determine the social aspects - and you could have caster backgrounds that bring in the spells that affect that pillar, as well. A third choice could deal with the exploration pillar, perhaps?
