People work is easier to shoot with a full-frame camera. And in my opinion, FF people work looks "better" and more professional. More traditional. Better selective focus, especially when you're forced to shoot in bright sunlight. Lenses perform as they were designed to do on FF; a 50mm is considered a very short telephoto (by Canon itself), and the 85mm 1.8 is also a telephoto. Take the 85mm lens for example: with a 1.6x Canon 7D, you must stand about 34 feet away in order to frame a six foot tall standing subject, and at that DISTANCE on the SMALL format camera, the depth of field is great enough that the background will compete for attention with the subject. With a 5D or 5D-II, the same 85mm lens will allow you to shoot the same six foot tall standing person, but from only 20 feet away! At that CLOSER range, with a 2.3x LARGER format, the depth of field behind the subject is significantly shallower.
The same situation exists indoors, using wide-angle focal lengths, only worse. You really want a FF camera for people work.