It's just another legal way to make one's self feel superior over other human beings. Their is no logical reason why people want to disregard youth as inferior, other than to help make themselves feel more superior in life or in arguments. Just like racism or sexism...one person takes in the mindset that because of something they have that they do not, that they can say they are superior to them because of...and you better believe they try to reap as much of it as they can. Once they feel they can pretend that they are superior to another being, especially in a setting that seems generally RIGHT in mainstream society, the degrading of the other party is imminent. There are many people out there that feel they need to be top dog in society (or actually believe one thing is inferior to another due to upbringing) and will do anything they can to climb their way to the top, even if it means degrading a bunch of 9 year old children for doing nothing wrong. I honestly think this is one of the worst things, because at younger ages children are taking in everything about society...and if they keep getting told they are inferior to older person(s), this mindset will sink in quickly, and could even cause depression, or lead to suicide. It is like peer / social pressure, but since they are still developing, they believe the insults much easier.
Also reading the article about voting...I honestly feel that no one in this country should be allowed to vote without passing a test about government, and other related issues that coincide with what you would be deciding to hand over to officials like the president, or a governor. This way only the people who know that they are doing can vote...the decisions of the country are made by intelligent people, and their electors should have that same mental capacity. I don't care if they are 4 or 40...if they can't pass the test about government, they shouldn't have a say in it.
With age is supposed to come wisdom, as you tend to have more life experiences...but this doesn't disqualify youth from being intelligent, nor does this make them unequal in society. In life you tend to forget things, and have a general mindset based on what you do daily...so I would honestly believe in all around intelligence about subjects most youth would actually be MORE involved and intelligent than most adults, as their general focus is school, while the adult's focus might just be their job. Everyone is proficiently intelligent or good at different things, some more than others, but to a point where everyone has different skill levels in anything you can think of. Age isn't a factor in knowledge, it is the amount of time you spend in devotion to LEARNING about what is around you that counts. There is no reason why anyone should be degraded in intelligence because of just age, the only time intelligence should be negatively noted is when a person has NO want to learn about anything.