Yep, you're right. But, the essence of the thread may be of interest to some current members. Both granite and marble fare better when substrated with plywood. If the cabinet height is 34 1/2" (what is needed for undercounter appliances), a total thickness above that should be 1 1/2". An add on buildup for a bullnose, or some other profile gets epoxied on and ground and polished. The back edge of the buildup hides the front edge of the plywood. This is a very common practice.
The plywood can be screwed to the cabinets and the granite is set in adhesive caulk, like Polyseamseal.