I have 2 reasons I went cabinets first,
-I am tall, so I put my cabinets on a 2 inch high platform. so now countertops are 38" off the finished floor. which is awesome. it should be the new standard, even my short wife loves it
-I used expensive wood floor in the kitchen. so no reason to put that under the counter tops. saved me a few hundred

I did put it under the fridge.

I put mine on a platform made of 2x4 and 1/2 inch of plywood. my countertops are now at least 38 inches tall, its amazing. no one has ever said they are too tall(wife is 5'3") and my back feels amazing