I believe the auditable nature of the blockchain is part of Bitcoin's success. The transparency is useful and ideally organizations will adopt bitcoin as a counter to internal corruption.

It also makes the protocol simpler and easier to work with. Transactions do not require negotiating view keys or any other additional steps in order to coordinate with others.

I think it's easier to add a layer of privacy than take it away. Imagine if the world ran on tor by default. I love Tor, but 90% of my traffic does not need to negotiate complicated circuits and rendezvous points, I just want it to get from a > b as fast as possible.