The benefits not being that big are a big part of it. Yes, if there was some hugely compelling reason to create a moon base then a 20% loss rate would be fine. But there isn't. There are no resources that would make it worthwhile, and I don't see the "national pride" argument supporting that kind of cost. That's what Apollo was built on, and that got canned after only six landings. And they had the USSR to compete with, so I'd think the "national pride" motivation was much stronger than it would be now.