Because people don't have real power, it's all indirect through politicians who are manipulated or paid by professionals.
Democracy should be direct and the gating function shouldn't be age but a test of intelligence, logical reasoning, general knowledge and ability to detect manipulation.
1) Do they really? I honestly don't know, are there independent polls about this?
2) What makes them think they have any right to decide for other people's children? I would be OK with them genuinely thinking they need to surveil their own children but if 1) is true then there is this underlying need of people to control others and I am not OK with that. This is how minorities are suppressed and harassed - same mechanism, different target.
