Considering that she's a well known apologist of mass surveillance, what you're saying is that maybe they are simply using her and abusing her trust to undermine her own positions.
That's not exactly reassuring vis-a-vis their ethical character.
Leaders of large companies usually have to manage a wide array of disparate and sometimes diametrically opposed interests.
The guys at Dropbox are smart; isn't the "obvious" assumption that Rice could be useful in helping them to better manage some of these interests (e.g. potentially reducing govt. snooping by facilitating a more level playing field for comms. and negotiation)?.
If by reasonable, you mean "rational" in the sense of rational choice theory, and if by "utilitarians" you mean "maximize of their own individual utility" rather than "adherents to the philosophical school of utilitarianism", then, yes, all reasonable people are utilitarians, by definition.
That's not exactly reassuring vis-a-vis their ethical character.