There's a big difference in scope and impact between merely teaching somewhere and being on the Board of Directors and running it. It's not equivalent.
She was Provost there from '93 to '99, which is a little more than teaching [1]. I think that while her willingness to go with the Bush administration's extremist positions (on torture and surveillance, especially) are a dark mark on her career, Dropbox is worth dropping for wholly different reasons (e.g. technical incompetence [2]) than who is on their board.
1. "As the chief academic and chief budgetary officer of the University, the Provost is responsible for administering the academic program, including both instruction and research, and for the coordination of the administrative and support functions of the University with its academic purposes." (https://provost.stanford.edu/)
To be fair, though, her provost tenure there was before her tenure in the Bush administration, where her most egregious acts took place. You can't blame them retroactively for not knowing what a monster she would reveal herself to be in the future.
I disagree. As a professor at Stanford, she's teaching the future rulers of the world how to rule. At Dropbox, she's showing up to board meetings and taking a salary.
Her teaching at Stanford is the same sort of trophy namedropping photo op that being on the board is. You can't actually get a PhD in Hegemony from school.
