Something about the mechanics of 1e or 2e gating of minion-status via HD vs 4e's iteration of the same...or something else.
When you think about it, the dividing line for 1e minion status was the line between the 1-1HD goblin and the 1HD orc. Below that line, the fighter got 1 attack/level vs the little suckers, while above it, just the same attack routine as vs any other foe, on up to dragons &c.
It was pretty stark, really, yet it hardly mattered. Those minion-level monsters had the worst attacks in the game, low hp, were dreadfully susceptible to Sleep, fireball, Cloudkill, Deasthspell, &c, and were just generally pretty much meaningless. In theory, a 9th level lord whacked 9 goblins a round, in practice, they were blown up before they ever got that close, or just ran in terror from the party....
....or, hid in their deep warrens, filled with traps, and snuck about and you never get 9 of them in arms reach at once...

It was nice in theory, in that you could picture a fighter standing atop a mountain of bodies like Conan on the cover of some REH pastiche, but it didn't much deliver.
The big difference with 4e minions - like the similar mechanics introduced by games like FengShui or GURPS Cinematic a decade or more prior - was that they were designed relative to the PCs. Now, TBF, everything in every TTRPG
is relative to the PCs, they're what the players experience the world through, but 4e minions, and monsters in general, were designed to work with that. So a monster that was a terrible danger facing down a party by itself at low level, could be a standard you fight in groups at higher level, and part of a horde you plow through at the highest levels. That fits the intended zero to hero trajectory of D&D, it fits some examples of genre - series, particularly, where the first time a monster is encountered it's a big deal, but the more the same sort shows up, the more of 'em it takes to be scary and the faster the hero dispatches them - but it's not something other editions of D&D actually tried to design, too.
Ultimately, for all the consideration the pile-o-bodies fantasy is getting, it's never been done well by any edition of D&D, not as a thing for the fighter. A few flashy AE spells deal with such enemies a lot more efficiently, in every ed.