True and not true. The game auto-detects your PCs power and sets additional options accordingly. You can find these options in C:\Users\[user name]\AppData\Local\LAG\data\settings under the renderer_settings.xml file. Changing them won't help with the ugly texture pop-ins or most performance issues, though, and there's really no reason you shouldn't be able to change these in game.
No one said you couldn't change them via an ini script or console commands. The minimalist menu is due to the console port and the approach that was taken by id for their new engine -- run on any system, optimized, at 60fps, targeted to consoles.
I think after seeing all the bugs and issues all of us can sit back and safely assume the port wasn't given much effort, the menus, the game, heck even the starting screen where you have to press Enter to exit the game, all feel like a console.