Because the number of senile/crazy people voting is a tiny percentage. The 16-17 year old block is potentially much larger, and might actually swing an election.

I share the opinion of many here that almost all those below 18 are too ill-informed, poorly educated, and immature to deserve a vote. They'd be easily propagandized and peer-pressured into voting poorly. That's not to say that many 18 and older don't fall into the same category, but we don't need a new large group like that.

You did not read my comment. I called out a case for limiting the upper ends, but I guess your emotions responded.