I think it is genuinely an immaturity issue. I am strict in that I will always do the takeoff and landing. Sure I don't mind sharing the workload but they do like to take control in the air when they feel like it.
I guess everyone likes to think they are better than the next person! The guys i've taken up who are LEARNING will gladly take it all in, sit quietly etc but it seems as soon as they get their licence in their hand we get 'it's alright i've got this covered!' sort of thing. It's like I no longer have a licence!
PS...I only have 130 hours TT but the lads I am talking about have only recently qualified and around 70 hours.