Here are some of the more spirited comments from this video thread:

Commenter panda had this to say:

What if every planet in our solar system is inhabited, but they aren’t that as stupid as to just live on the surface, or are so smart that they have technology that makes us think that they don’t exist.

Commenter Lightzz had this to ask vsauce as well:

Why do we always assume aliens would come to trade off knowledge? Don’t we ever think they might just come to slave us? Kill us? Get our resources? I don’t know, it seems meaningless to go visit someone just to say hello right? There has to be a more valuable reason behind the visit.

If nothing else this gives us a lot to think about.