We experienced this last year, 11u, so be thankful you got a few more years reprieve! I can only surmise it had to do with what lefthookdad was talking about...when the boys started seeing serious teams and the coach had a serious talk with them in 12u this behavior mostly disappeared on the ball field. As for at home, a few threats about what would happen the next time the kid rolled their eyes, or walked away in the middle of a conversation they were done with but a parent was still talking, seems to have fixed that glitch....at least for now.
I will say that if no one *like the coach* is addressing this behavior on the ball field then yes the bad behavior is likely to continue while the 14 year olds think they are hot stuff. On sons 12u team coach doesn't care who the kid is or how they can produce, you show attitude to an ump or a coach, or have displays of eye rolling or pouting, and your butt is riding the pine.