Why do children have a sense of entitlement?

A lot of young people today have a sense of entitlement. No one I talk to seems to know why. I have a few ideas.

It starts when children are toddlers. Parents take their kids to restaurants and they let the kids run around and cry without doing anything. This creates a sense of entitlement. My child is entitled to do what he/she wants without any regard to anyone else who is trying to enjoy a meal.
Parents

It continues when they enter elementary school. Most after school activities are age appropriate. Parents don't care about the age range for an activity if their child wants to participate. They sign them up for the activity even though it is for older children. My child wants to do this, therefore I will make it happen! Parents don't care how having a younger kid in a class will affect the instructor and the other kids. My child is entitled to participate in whatever activities that he/she is interested in.

Parents don't seem to have a problem telling their child that they have too much homework. They also don't mind telling the child that they can turn in the work late because it was too much homework. That same parent will call the teacher and expect the late work to be accepted and without points being deducted. Children are entitled to have only enough homework that is convenient for them and their lifestyle.

High school is when the excuses for bad behavior kick in. My daughter is entitled to be mean to her friends and teachers because it's that time of the month. If this is true, then your daughter is going to be a lonely single woman until menopause.
My son is entitled to punch his classmate because he has ADD. Bad behavior is unacceptable and there should be consequences, not excuses because your child has ADD.

Parents with children at every age level have demanded playing time for their child in various sports. Just because your child makes the team, that doesn't me that he/she gets to play the entire game or even play in every game. When your child is playing on a team he/she is not entitled to the amount of playing time that you deem appropriate.

Parents, when you allow your children to do whatever they want, whenever they want, without any consequences or boundaries, you are creating a sense of entitlement.