Canvasing of consumers indicated that a living room adjacent to the front door, a holdover of the Victorian parlor, was far less important than having more space in a great room. Without reconfiguring the outline of the building—changing slab designs is costly—the front parlor was transformed into a smaller office or guest bedroom. This design makes sense, as the front door is typically not used for entry these days, but as a marker of domesticity.
I have been studying what I call "boburbs" - the dense, walkable, mixed-use neighborhoods favored by the bourgeois bohemians - the bobos. These houses tend to come from an era in which the front porch was a real room, in talking distance of the sidewalk. The residents walk up to the front door from the sidewalk for a variety of reasons, not just as the path to the car.
I agree with Alfonsin that in many car suburbs, the garage or the side door nearest the driveway is the normal point of entry. But in the boburbs, front doors are still real main entry points.