It's true of all major brands today. With layers of luxurious latex, visco memory foam, and other new materials, even basic good quality mattresses start at 10-12" or more, and many of the fancier ones can be 16", 18" even 20"+ thick. Add a standard box spring (9") and frame (9"), and it's over three feet from the floor to the surface. Aside from an uneasy feeling being perched up so high, for many people, it presents a physical challenge getting in and out of a bed.
A low-profile box spring is about 3" thinner than a standard box spring, helping to reduce the overall height, without sparing any of the mattress features that help bring you a great night's sleep.
All Create-A-Mattress combinations are available with a low-profile box spring for the same price as a regular box spring.