It remains anonymous for the moment but that is all changing as Shapeshift comes under pressure of the criminal entity called government and their enforcement agencies.
Once KYC comes into effect they will experience a mass migration away from their platform.
Their business is dead unless it decentralizes (which I hope it does).
This is the number one problem with centralized businesses. They are prone to attack from the state.
See how great regulations work? Protecting people from freedom and privacy every where.