This speech is basically a rallying cry given to women to stand up and claim their righteous place in American society. But unlike other rallying cries we're used to hearing (say, "Give me liberty or give me death!"), it's given in a nurturing, inspiring tone.
It's like she's just gently reminding the graduates that it's time to seize the day and to embrace the "other" side of society—the side that has been relegated to women because men are either too scared or unable to acknowledge it—and by embracing it, finally achieving equality with their male counterparts.
After all, according to Le Guin, our future lies with women. (Who's betting that Le Guin owns at least one "The Future Is Female " shirt?)
Le Guin thinks women are better than men, and that's why they need to step up.
Le Guin thinks that society needs a better balance between the male and female strengths, but one is not necessarily better than the other.
It's the beginning of the end of the Second Wave of Feminism. (Don't worry: there'll be a sequel called the Third Wave.) The social reforms that have been accomplished in the name of equal rights are impressive, but not enough. So when Le Guin is asked to be the commencement speaker at the graduation of a well-known women's college, she has some things to say about what it means to be a woman.
Le Guin wants to make it abundantly clear that now is the time for women to claim their own place in American society. They need to stop fighting for success as it's defined in a man's world, and instead get more comfortable with what it means to succeed as a woman in a woman's world.
She advocates separatism, to a certain degree, in order to establish places where women can be women without the patriarchal framework upon which American society was built, so that they can finally achieve their own level of greatness.
Plus, you know, the future lies with women. (Men would have an awfully hard time trying to procreate on their own…)
Le Guin says women rule…so let's stop letting men boss us around.