One accomplished person should not be belittling the accomplishments of another.
A good check to see if something is a joke is to see if you thought it was funny. To me it looks as if he wants to make this seem totally insignificant, and to increase his own stature by appearing to be above (pun intended) this all.
That doesn't even make sense.
You're just being needlessly and nonsensically indignant over a joke from a guy who is hardly unaccomplished himself [1].
Chill out.
1: http://en.wikipedia.org/wiki/Neil_deGrasse_Tyson#Selected_aw...