As the owner's engineer on new developments, I get to review and comment on the design elements.
One aspect of modern homes is that with a large main floor area, architects and designers somehow feel compelled to have a full basement underneath and therefore end up "making up" uses for the huge basement footprint. So we end up getting a basement with a store room 1 and store room 2, a rec room, a media room, a kid's room, a sitting room, a basement bedroom 1 and 2 etc.
Generally, no one hangs out in the basement because without direct access to the outside, it's just not comfortable.
Attention should be paid to what makes sense and how we actually live in a home. In most cases the main floor can be slab-on-grade or on a crawl space. Sure a basement with an extra bedroom, media room, storage and general rec area is OK; however, for a large home (say over 5,000 sq ft), to duplicate the entire main floor perimeter below ground should be questioned.
I don't want to take away from a living large lifestyle, but I do recommend it be done at grade level!