Just plain ordinary lack of manners by the parents.
To alot of them, these kids are their Gods and could care less about anybody but themselves, thinking their kids walk on water.
Was eating out last week with my wife trying to enjoy a nice dinner.
Little kid about 7 acting up, disturbing everybody and the mother does nothing.
Finally the kid starts hitting her mother.
Mother says, now your not getting any dessert.
Kid keeps hitting her, Mother says now we are not going to the movies.
Kid keeps hitting her, Mother says, you can't play with your Barbies when we get home.
Kid kept hitting her knowing she had so many toys home it didn't make any difference.
Went on for what seemed forever.
Spoiled kids, parents fault.