Ellen Pao is either lying about her motivation by attempting to underpay her workforce, or perhaps she is just an idiot. When she says, "Men negotiate harder than women do and sometimes women get penalized when they do negotiate," she is first being sexist, then undermining her own credibility as a policy setter within the company. First off, it is blatantly and horribly sexist to make a ludicrous blanket comment like that when she claims to be striving for equality. To then admit that her underlings might penalize women for negotiating for themselves is an admission of failure.
That, or she is simply looking for an excuse to refuse to negotiate in good faith, thus making it easier to underpay everyone across the board (and miss out on valuable talent, of course). What a load of crap, which should not be unexpected considering this is Reddit we are discussing, I guess.