I think what this boils down to is you want to punish DropBox for some things that Rice did 10 years ago that you disagree with.
Rice was part of criminal administration. We aren't talking about philosophical differences, they were crimes. Rice may not have been robbing the bank but she was still part of the gang.
Any company putting Bush, Cheney, Rove, Rumsfeld or Rice on their board is going to lose my business.
Maybe you missed it but she was also the National Security Advisor at the helm when the US was attacked on 9/11. If that represents the clarity and competence she brings to her job on the board, this is not a positive development for Dropbox.