When I learned about Bitcoin early last year, it was being touted as a privacy solution. Though, the last I remember hearing this doesn't really stand up too well. Perhaps the issues have been resolved? I don't know.
However, for me personally, it solves the problem of my curiosity. That's solution enough.

Bitcoin is much more private than credit cards, paypal, checks, ACH, bank wires, and other digital currencies.
It is less private than physical cash, gold, blood diamonds, etc.