Bailey, just take a minute and breathe. You seem pretty upset by somebody's comment, but it's not clear as to whose. No one challenged you or diagreed with you, so I am really unclear why you seem so upset.
In the meantime, let's clarify a few things because your errors do make me question the validity of the things you have heard.
1. Pioneer is a junior high school, not a high school.
2. Most 10 year olds are in fifth grade, which is not junior high school.
If you are deeply concerned about the sexual development of children, I would suggest that you read up on the subject. Knowledge is power. Casting aspersions, not so much (sadly, I know from experience). When kids that age are engaging in sexual behavior, it is usually because they have been sexually abused themselves. In some instances, it is from being exposed to such things via TV, music, movies, the Internet, etc. While I can certainly understand not wanting to place your children in that atmosphere, there is a difference between isolated incidents and prevailing norm. If it's prevailing norm, not having the kids go to that school makes sense. Isolated incidents bother me (the only person I can speak for) less and they can be used as "teachable moments."