Very interesting, Robert!

Why do we send the robots?

What matters is what we acquire and can use for future generations. What we enjoyed at one point and couldn't use later is only part of the learning process (I think of punctual spectacular and emotional moments which later loose their meaning).
But what we must acquire and will keep for later is :knowledge.
Knowledge is what matters most of all and what future generations will use.
But how do we get it? Well, the cheapest, the fastest way possible!
After all, as you suggested, it's not the robots who learn or need the information, it's us humans! And if robots can virtually take us anywhere we want and help us acquire knowledge as well (if not better) as if some of our representatives had been on the spot, instead, then go for it!
But humans could also go there, though perhaps not as much for the purpose of knowledge as for the reason of personal challenge.

Raoul