As a relatively new shooter, I have not had Range Officers disturb my enjoyment. There are good points above about why RO's protect the club's existence, but I'm surprised no one mentioned one of the reasons for RO's - that of keeping you safe from other fookin eedjuts (the correct Irish pronunciation). We've all seen a group of younger shooters who all recently started buying guns and have no idea that they are being unsafe until a RO points out the violation. At the indoor location I shoot most often, the rules are always explained to each shooter. It is amazing to me how often I need to go talk to an employee about a rule violation one or two lanes over. The employees must get tired of having to tell people the same thing repeatedly, which may come across as "attitude".
Life is different than when we kids rode our minibikes on any open property and shot BBs and 22s anywhere we wanted. An overly zealous (and some might say authority hungry) RO is more a symptom than a root problem.