I graduated from a Catholic high school of 1200 ~7yr ago that in my last year actually used a similar RFID-tag system for the doors (was already using plain bar-codes for the cafeteria). AFAIK the (stated) purpose was access control; RFID makes a bit more technical sense simply to keep the doors from backing up or bar-codes getting muddied up (not that it kept the things from breaking continuously anyway). No one ever raised a fuss (not to say I personally agreed).