I believe the commenters so far have failed to address the main point: the devil is in the details. And everyone knows why the details suck in this category of

I believe the commenters so far have failed to address the main point: the devil is in the details. And everyone knows why the details suck in this category of McMansion: they are spec houses designed by beancounters. They represent the aggregate current view of what would have maximum curb appeal. That is the only design criteria for such houses.