Matt Moylans dead ball on friday

I don't get the hoopla surrounding this rule where the ball has to bounce on the ground over the dead ball line in order to be constituted as dead. Why are people so miffed by Moylan being called as the one who made the ball dead? If we're to suggest the ball is dead even while still in mid air, tries like this would never be awarded:

https://www.youtube.com/watch?v=hoiaECEyhgc

Matt Moylans dead ball on friday