Argue with them and you won't get to play. You have to listen to what they tell you, they are there to ensure that everyone has a good, safe day. As parents we want our kids to learn the lessons of life, without getting hurt in the process. Well, I think it is, and paintball is the medium for it. These are all the qualities everyone should have.
Paintball is also a good motivator.
Kids who have played paintball have routinely earned better grades and have stayed out of trouble. Believe me, there are worse things for kids to do. Given a choice between the two, I'd rather have my daughter buying paintball markers and paintballs than pistols and crack. They're not allowed to be intoxicated when they play paintball. In playing paintball they will learn all the important lessons they need to carry with them for the rest of their lives, without getting physically or emotionally scarred for life.