I think it is about boundary setting Mick. I agree that sometimes people will cross lines that you would prefer not be crossed.
Some may do it because they are just trying to help.
Some may do it because they think they know the answer or "right way".
Some are controlling, some are opinionated, and some just love drama.
All I know is that if someone crosses a line it is best to let them know in as tactful way as possible so they get a clear understanding of just where those boundaries are.
Just my opinion :)