School Policy : No tank tops! What The Flip?

One of the policy's at Olympian High School is not being allowed to wear tank tops that show your shoulders. Why is that? Seriously how does that disturb class or students? Tank tops don't do anything but help us stay cool and not only in a fashion sense way but also in a " its freaking hot outside why the heck would I wear a sleeved shirt" way. I think this rule is totally abstruse when it doesn't have any logical reasoning. In my opinion Olympian should just accept that yes, girls and guys of this generation like to not overheat and show our shoulders.