The teachers aren't trusted.
Just my imagination, you say? Case in point: All teachers are required to sign in and sign out on an electronic scanner that recognizes your fingerprints. Also, there is no stack of copy paper next to the copy machine; each teacher is given one ream per semester. (If you run out, too bad for you!) This means lugging around heavy paper every time you need to make copies. And the biggest inconvenience? We're not allowed to have a building key, so if you want to come in and get caught up on a Saturday, forget it! You're there to steal computers, for all they know!
If you need basic supplies for your classroom, like copy paper or printer ink, you practically have to beg the front office for it. If they deem you and your cause worthy enough, they will unlock their secret supply closet and find what you need.