Originally Posted by something
It served two purposes for me: 1) comedy, and 2) showing just how huge a deal the mastery of nen is. A skilled nen user in a sea of novices who have never heard of nen and who don't have "Protagonist Armor" is like pitting the World Heavyweight Champion in the ring against a bunch of tired toddlers. See for example what a joke it was for Hisoka and Izumi to pass, when they didn't have to deal with plot-significant characters.
Oh right, normal contestants don't know Nen yet. It still seems like they could've thrown in someone
on par with Hisoka or Izumi during the original Exam. But really, I'm just more confused why it was thrown in at this particular moment.