The fact is that people get more mature with age. Of course there are some minors that are more responsible than some adults-its not an iron-clad statement that no minor is as qualified as an adult, but the fact is that the average adult is more mature than the average minor. This bill wouldn't solve the problem of immature people operating rides, but trying to say that minors are just like adults isn't close to being true.
And there are other reasons why seniors will skip more school than freshmen: one-they have cars, two-they've been in school four years longer and are more burnt out.