I suppose it's looked as "Well you don't own the view" even if you have had uninterrupted views for some time, years in fact, if your administrator did stop this person surely this could have a knock on effect if you wanted to do something on your terrace, Sat dish for example, they could say thats ugly "Move it".
Could cause unnesarry friction even if you approached your neighbour and asked him to remove it..."F*** of" I would expect the answer to be, and after all the administrator has to keep the peace with everyone I suppose.
Live and let live, comes to mind.