Let's be honest with the real reason people don't like cadets.
When you meet in flight planning for the first time and do the intros it inevitably comes around to what were you doing before this? The cadet has a freaking boring story!! Oh cool you flew a C172 for 150 hours! Amazing....
Who doesn't prefer a bit of a Kunnanurra, Broome or Alice Springs story involving various European backpackers! Plus the potential story of there I was and it was all going wrong!
(Also, anyone who says a cadet is equal to someone who has real world experience (on day one in a passenger jet) has rocks in their head)