Where Can I get Simple Graphic Tees?

You would get a better response I think if you post in the Streetwear & Denim section.
Personally I think GQ is a magazine masquerading their commercial ads as fashion tips so buy and wear what you like.

Wow, that's an ugly shirt.

Though it's not SF approved, I do have graphic tee shirts. If not baggy and way oversized, they can work as a nice bit of summer casual. But only the right ones. The ones I wear are college tee shirts with a script across the chest from my alma mater, one from my brother's, and a navy shirt with a big yankees logo and nothing else. Substitute your own team for the Yankees, but keep it simple. No flames, portraits of players, or any other crap.

I also have a couple from here. Constantly changing selection, and some are better than others, but they're better than most, and on American Apparel shirts, which are nice and slim, and are built well.

Graphic tees, done right, are whimsy and Americana. Done wrong, they're fat American slob. Choose carefully.