I don't think money motivates her exactly, but being paid less than the next CEO guy would demotivate her (yes, it comes to the same thing and no, her needing less won't force her to pay more taxes). Pecking order in the peer group matters to most people. That said, I think as a group CEOs are overpaid wrt to the value they bring to shareholders, but boards are made of CEOs, which explains why the Gini keeps rising.