Perhaps Andressen is not aware of how effective and secure Dark Wallet is supposed to be....?
Perhaps Andressen is personally funding startups that will do everything they can to datamine the blockchain, and believes the resources they have at their disposal will defeat anything Dark Wallet can do.
Maybe Andressen has reason to believe that they can block any changes to Bitcoin that would make data mining less effective by having an understanding with key developers.
Good point, justusranvier. Sounds to me like an epic, high stakes battle with tons of wealth on the line.
Also, early users of Dark Wallet will not know for certain if they are completely secure. Perhaps in the future: Libertarians and Governments really will
swap what they think about bitcoin.