Most people do 20 to 30 sets for their chest, same for back, same for quads. 15 to 20 sets for bi's and tri's. Then do 2 or 3 sets of calf raises and wonder why their calves don't grow.
Same for abs. 15 to 30 sets for every other body part but 2 sets of sit ups and wonder why they don't have great abs, of course abs require diet more than anything but still. If you want those muscles to respond the same way chest, back, arms, thighs then you have to train them with the same sets, reps and intensity- if not more for calves.
I think mentzer also commented that you spend your entire life using your calves when standing, walking, running, playing a sport etc. They get work everyday of your life, they're not going to grow from a few half-hearted sets.