People like to criticize Dropbox's appointment of Condoleezza Rice for much more substantial reasons than American party politics. 'Drop Dropbox' [1] offers an overview that, while biased, does address that accusation in particular.

A lot of my personal moral concerns with Dr. Rice's appointment are as a result of actions she condoned or advocated for during her time in government. Don Knuth's letter to her in 2002 expresses my feelings on this topic much better than I think I can myself.

[1] http://www.drop-dropbox.com/

[2] http://www-cs-faculty.stanford.edu/~uno/rice.html