You should always vote against improving the lives of those younger than you at the cost of your own well-being, since you will never be younger than you are now.
Some people care about the wellbeing of others. Even strangers (gasp!).
This often leads to local maxima where even the person who is optimizing for his own selfishness is losing overall.
Pretty sure this was a satirical post you guys, of course the youth are more important than the old. They're the only ones who can reproduce and ensure we have a strong civilization for thousands of years to come.