I think you seem to have widened your definition of Moe hugely.
Yotsuba and Azumanga focuses on the comedy of life as opposed the cuteness of it. It seems that people have different definitions of what Moe actually is.
To say artstyle is moe, well, it is to a degree. I mean in general. When you have grossly exaggerated features to highlight cuteness, then I suppose this is what you can call Moe these days. Mikuru is a perfect example of this.
Azumanga and Yotsuba have very simple art, almost like a webcomic. There is nothing sexualized ever about them. It's all pretty much down to earth. The only time I ever recall anything remotely sexualized is Sakaki's glorious breasts, and how Tomo keeps mentioning how big they are. I don't EVER recall a panty shot. And panty shots are insanely common in anime's these days.
Chiyo chan, is cute, she is supposed to be cute, and it's part of her character to be unintentionally cute. Although I wouldn't describe her as Moe.
Yotsuba, is incredibly down to earth and pretty much focuses on the world from Yotsuba's point of view. Again, there is never anything remotely moe about it. The art is very comic like and simple. It doesn't bother highlight any sexual or cute features.