I would take any public review site with a grain of salt. It is someone's opinion, and their option will be coloured with emotion. Like ofthers have said people who didn't make Team and left, people asked to leave gyms because their children behaved poorly or they didn't pay their bills, kids who were not allowed to attempt advanced skills because they lacked the nessesary strength to make it safe, kids who got annoyed because their friends moved to a higher level and they didn't. All of these people love to make bad reviews.
I would also be very, very against any site that gave people access to information about a coaches history, except for those who have in fact had their allegations proven and have been banned. If a coach is suspended pending an abuse accusation, that should not be free public information until such time as those allegations are proven. These days it is very easy for an unhappy gymnast or family to call abuse, and true or not it can ruin a Coaches livlihood. It happens to school teachers, especially male school teachers.