It's less about ensuring that students are at school, but ensuring that they are counted. The school district receives funding from the state dependent on attendance. That's what is meant in the article by "it's all about money". With the cameras and now RFID, they can record that the student is on the premises even if they are not in the homeroom for attendance taking. (There are legitimate reasons a student may miss roll call.)

taking attendance doesnt allow you to boast about how you are being proactive. It also isn't a reason to ask for a big budget increase.