I'm not sure he's a bullshitter exactly. He's wildly overoptimistic and is immune to reality to a large degree. The thing is, those can be really good traits for advancing the state of the art and developing new things.

If he wasn't like that, he might not have done some of the worthwhile things he's done. I definitely wouldn't take anything he says at face value, but I think there's value in him being like that.