Yeah, there's the whole farm-to-table movement, CSA's, heirlooms, farmer's markets, and even the preppers.
Some of what I grow is readily available elsewhere. But, the flavor, freshness and varieties are not. You can't buy a tomato that matches the taste of one from your back yard. The varieties available to a home gardener dwarf the measly selection at the store. If you saw the pics of my garden in the other thread, you can tell I'm not cranking out produce in quantities big enough to reduce the grocery bill by much. I mostly do it for the fun and satisfaction of it.