Celebrim
Legend
Or maybe just didn't care.
But it's not /that/ complicated, really, just arbitrary and inconsistent.
Well, I don't think it was that they didn't care. They cared, but they weren't thinking in the terms we are thinking in now. Some of the language we employ hadn't even evolved yet.
The words I'd use to describe it would be mostly organic and evolved. This is a system that's being built from scratch through play without no prior guide as to what an RPG system is like. New things come up, and they are dealt with on the spot, new ideas jangle around in the back of Gygax's head, and then he gets an opportunity to try to put all this experience he has built up over years as a DM onto paper, and what it ends up looking like is a rules equivalent of a collection of very early airplanes when people weren't exactly sure what shape an airplane needed to have to function well as airplane.
The thing is, some of those rules are actually really well built evolved solutions to particular problems. And others are just cobbled together with bailing wire, string, and tape and are pretty ugly. And some are like those planes crashing off the end of the pier in a mass of collapsing struts.
But my point about the complexity is that it meant that to analyze the situation while not complicated requires an enormous amount of time, even in an era with modern spreadsheets and scripting out solutions to analyze data. Beyond that, I think all that complexity helped obscure the idea of how you'd go about analyzing it in the first place, or even that you needed to, because everything was created in play and tweaked in play and everyone was used to just relying on their gut. Nobody had the habit of doing the math before hand, and it's not until the 80's that you start to see in Dragon people start advocating for these mathematical models to inform design. That's not to say that I think there is no math and forethought in Gygax, but I don't think even in the 90's that everyone was in the habit of analyzing a system in that fashion.
But if you do go read some of those Dragon articles, they are hugely informative and I wish looking back I'd paid more attention to the seemingly boring lists of calculations that people were doing to prove various points. I might have actually produced house rules for 1e coherent enough that I wouldn't have left it eventually in frustration.