I'm going to give an opinion here that has no evidence- so consider me devil's advocate-ing, I'd love to see contrary evidence. I have long suspected that Chris Hadfield has been phenomenally popular among the tech-inclined, tweeting classes- but has had a far smaller impact on the 'everyday' person.
I do not mean this as a slight to him in any way- I think he has done everything and anything that he could. But the mainstream media seems uninterested- the height of the NASA space faring days was when there were about four TV channels anyone watched- the mindshare it captured is incredibly difficult if not impossible to replicate today. It's very sad.