Most parents believe it will help thier child develop without the risk of shock or harm. Of course they are wrong,over protect and shelter to much you raise a unreasonable person,who hasn't got a clue what the real world is like,many of these children can not cope with reality,because they have never encountered it before. I have an extended family member who is raising 3 sons in this fashion,they are intelligent,but can not cope with something as simple as making an appointment,mom does everything for them and it shows. They are 19,16,and 12 yrs. Of age,and there is no difference in the way they behave. They expect everyone to just bow to thier will,they have a tough road ahead because mom wouldn't allow them to be main stream,over protecting your children is paramount to abuse the way I see it.
Some do and some don't. It also depends on the kids age and mental maturity. There are certain things in the real world that kids don't need first hand knowledge about. Some adults wish they would of had more of a kids life when young because they had to see the real world. I feel, when a kid is out of high school he can decide on his own what and not what to see in the real world.
Because back when I was a child, the only monsters we worried about were the ones hiding under the bed or in the closet. Now there the monsters are everywhere. And now they wear disguises.