There are 19 year olds with TS clearances. Some jobs just require it. It can be written into an enlistment contract. National guard and reserve units of different kinds are also kind of known for having serious racism problems. Racists use it to network and meet other racists, get the training and some credibility without actually committing to active duty. That shit in active duty is not tolerated, usually cause it's actually diverse unlike a reserve unit in a place like Massachusetts.
Another problem with clearances in general is that often those eligible come from less diverse backgrounds due to parental citizenship considerations. fields that require a clearance are often less diverse because of this.
People who have some time in the military probably won't be surprised if the situation is what the media is portraying it to be. As Abraham Lincoln pointed out about the US, the biggest problems for the country will come from within.