Well, I imagine that if there were a compelling-enough reason to return to the Moon, there'd be an infrastructure in existence, just as there is for travel between North America and Europe.
However, there is not a lot of current economic benefit from visiting the Moon. It's not a resource of gold, or diamonds, or unobtainium. The advances to pure science are not currently considered important enough to make people want to spend the money to get there. If there were suddenly a Lunar gold rush, a technology sufficient to get us there would be rapidly created or, to be precise, recreated.