Oh please. Like Valve makes anything that's cheap.
Do you realize how much time they spend balancing and looking at how one weapon affects gameplay?
I don't now personally, but after listening to the dev commentaries and seeing how much time they put into everything else, I can only assume.
Well all the time they spent is obviously put to waste. I don't think they spent so much time, say, on the FaN for scouts to spam it 20 miles away, or the Huntsman, so you can spam arrows like no tommorrow.
On top of that, the Heavy and Medic updates were the only one "really" balanced.