Why can't they allow people who are balding to shave their heads in basic training.

I joined the Army and graduated basic training at the age of 37.  I am balding and have been since my early twenties.  I had been shaving my head since I was 27.  When I went to basic training I was informed that I could not shave my head.  Every two weeks the males would have to go get haircuts and everytime my barber would say "I should charge you half price".  I could have taken care of my own hair once a week with a razor.  So lets here it what does the community think is the real reason that we cant shave our heads in basic.