After being burned by ATI and Nvidia driver installs gone bad I'm reluctant to use anything but the defaults. Software SDKs too seem especially brittle when installed apart from the recommended options.
So it's not only casual users who prefer the default.
I would probably make an exception for driver installs, which definitely get into that "actually broken" territory. I'm also ok with "detect my device settings automatically".
I was mostly thinking about the program installs where 'advanced' is a list of different things you might want to install. The worst case there is pretty much just "you didn't install the thing you wanted", versus the "good luck buddy" worst case of tools and drivers.
So it's not only casual users who prefer the default.