A child’s self esteem can be destroyed by others not only by parents. Parents can be a child’s greates fans and they can still have low self-esteem and lack of confidence do to others or various circumstances.
Molesters groom their victims and they choose those who they are pretty sure will either believe them or will be too freightened to tell. It is not only a matter of parents not believing them it is also a matter of being threatened. Many are threatened that their family will be harmed and since they are being harmed they believe what they are told.