Because your school ran its own IT. In today's north america schools this is contracted out, or at least covered by a multi-school or district team who never talk to actual children. Any kid finding a flaw is a threat to that contract or system. Administrators dont want to look foolish, or admit liability for a flawed system, so they go after the kid (Modern privacy laws make them fearful of admitting anything.) Remember too that there is a culture in NA of adults seeing teenagers as a threat. They are suspect the moment they get to school. Any deviation from a norm only confirms that perception.