Who cares about any possible "successors"? I say we should put this archive on the Moon (or better yet, copies on the Moon, Mars, and all the geologically-inactive planets or planetoids in this system), not for us, but for any alien archeologists who happen to make it here, so they can document our existence and use it to learn about the mistakes of a failed civilization. Because if this information is ever needed, we'll probably have wiped ourselves out, and this planet is not a safe place to store such information as it'll either be destroyed by our weapons of mass destruction or by natural forces over time after we're extinct. If we actually do have successors, they'll probably destroy the archive when they get their hands on it, just like the Taliban do to everything historical they find.
Seems a bit puerile, like writing "I was here" on a planet then joy-riding home with a big grin on your face. Humanity just got over doing that on all continents, though it still exists in some small communities (eg. mountain climbers). We have a long way to go.
Leaving a complete historical record for your civilization hardly equates to writing "I was here". I'm sure Wikipedia's diligent workers will be happy to know that all their efforts equate to graffiti in your view.
As a Wikipedia administrator myself, I do believe it's important to take a distant perspective at times. The capacity to laugh at your own efforts and predicament certainly has value. At the time scales of the rise and fall of civilizations, one should not take oneself so seriously!
