Stellaris has the federation builders and violent imperialists! And humans that have delegated all high-level decision making to robots that pamper them. And sometimes humans that nuked themselves out of existence before ever leaving Earth.
In Halo's defense, the games don't really have room to explore the different subgroups of the various aliens. There's a lot going on in the books and other EU material.
Also, most people don't spend more time in space than necessary and fancier human ships wouldn't contrast as strongly again the purple teardrop shaped Covenant designs or Brutalist Forerunner designs.
Hey! There are a few episodes on TNG where a planet has two cultures at perpetual war with each other.
No pop culture since the 90s is accurate
Minbari have 3, plus various factions.
And blocky ships are just for anyone who's not brave enough to have WW2 battleships on space
I’d be bothered by the inherent jingoism if It wasn’t so fucking awesome.