Your bank balance isn't public. Your salary isn't public. Your rent payment isn't public. So why should your crypto be?
Discussion
Because governments can't help themselves.
I heard on vlad's podcast that you guys were doing spark. at first I was like, oh good now I can play with that on something open source instead of wallet of satoshi. but then I started worrying about your image as a privacy preserving wallet, because spark address balances are public