Hang on a tick here.
That's NOT what was being argued against. There was a shopping list of very fundamental changes to the game, half of which have never appeared in any form in D&D before.
We're not talking about a single change to one weapon vs a target with a shield (a completely pointless rule anyway since so few creatures actually USE shields). We're talking about a book that completely rewrites every single book and means that anyone using it would have to completely rewrite every published adventure that WotC produces. In other words, this is a book that would mean that it would be even more work for DM's.
It seems you are missing that
1) The rules would be optional
2) You wouldn't play with all the rules
3)The DM would choose which ones are in his or her game.
You really thought I was suggesting making 4 armor variants to be all added as core rules for everyone. I never said that?
This rolls right back into that horrible thread about D&D vs Bespoke games. People want D&D to do everything and they are for some reason shocked when the game doesn't really help them when they try to drift away from the central concepts of D&D. A humanoid dominated campaign? Since when has D&D ever supported that? D&D has always centered around monsters.
Good grief, humanoids make up what, 10% of the creatures in the monster manual? And you want an entire set of rules so you can focus on that and you want WotC to produce it? Good luck with that.
There are still tons of human sized fey, undead, monstrosities, and fiends. And tins of weapon and armor users if you just nudge up to Large size. Weapons combat for humanoid and monsters is boring in the
base system. Giants are still whacking stuff with big weapons and chucking rocks.
I still think the simplistic weapon and armor system is too simple for base D&D. Many people complain about the HP sponges in 5e. And because of action economy, just adding spellcasters is just a headache if you add more. Especially If you want to play them smart, with individuality, or with anti-player tactics.. And the opposite problem is true with the monsers are outnumbered and suffer action ecomony disadvantage.
So when my group hit the bosses of the gang that took over a mining town, I wasn't going through running 3 casters again. I cut out spellcasting and subbed in my "Anime Fighting Weapons Group Rule" into for the onis' casting. So once the minions got fireballed to death, they had 2 crazy interesting oni warriors and an oni spell caster to deal with.