Yeah, the blacksmithing area is one of the best things about Whiterun in my opinion. They have practically everything there!
It wouldn't surprise me if Whiterun was made to be the most practical city in the game on purpose; for most players, it's the first city you encounter. This always give you a place to fall back to. Other main cities come close, but all of them lack something, that being either a smelter, an alchemy store, etc. Whiterun has everything you'll ever need, packed into 5 or 6 buildings.