You know how there are "switch" comedies where two characters that are very different switch places? Rich and poor, young and old, single and married? It sounds like this Ghostbuster is a meta gender-switch comedy. In that context, Ghostbuster is almost a pretext to do something else and that's the main problem: people are more interested in a new Ghostbuster movie than in a meta gender-switch comedy.
I guess you can argue that the original Ghostbuster played on the "unlikely heroes" theme and using nerds in 2016 would not have achieved the same effect, unless you make them female nerds... but again, maybe people would have preferred a 2016 Ghostbuster that used the same type of characters than in the original film but made "ordinary heroes" out of them. It would have been an interesting angle, a nice opportunity for a kind of "recent history of the nerds", with the old crew's experience underlining the differences between the then and the now.