It's true, but he's got a point. Perhaps the Empire, once upon a time in Lucas's mind, was only concerned with human planets or planets with large human populaces. That doesn't really jive with my original or preferred take on the story, but the first two movies themselves could be read that way. The fact that they push a few jawas around while in pursuit of humans doesn't mean that they mean to rule over all aliens in the galaxy. And the name "Galactic Empire" could sort of be interpreted like "United Nations" or "United States of America." There are other nations or states in the area that don't belong, but that doesn't stop anyone from using the name somewhat globaly. Or galactically, as the case may be.