Originally Posted by
gungadin
Some infrequent fliers might not feel comfortable switching seats- might feel that it is " wrong". Your seatmate might have appreciated knowing he could move earlier.
I'd say this is the most likely explanation, especially given that the guy seemed unfamiliar with the protocol about placing bags on the floor.
Less likely is the possibility that he just didn't feel comfortable sitting on the aisle, with the possibility of being jostled a bit by FAs or fellow passengers passing by. But I'd still go with the inexperienced flyer explanation.