As soon as you start limiting people's ability to vote based on the perceived stake they have in the future, you start down a dangerous path.

It is discrimination by definition, whether you think it is justified or not.

The case could be made that not letting the people who will have to deal with the consequences for longer have a larger say is also discrimination. To be clear I'm not advocating for this to be put into practice however I do think that elderly should vote with this point in the back of their minds.

By this line of reasoning you could indeed decide to give less of a voting power to old people, arguing that all political decisions have important long term consequences.

There are plenty of reasons why that would be unacceptable, and I'm sure that's why human right conventions prohibit this kind of discrimination.

Is it really discrimination? Why do younger people get to make decisions with so little experience?

“A society grows great when old men plant trees whose shade they know they shall never sit in.” I'm curious how you will act when you have grand children.

You could easily make the argument that the younger people lack the experience to make sound decisions on the future.

You won't experience my life. So why should you get a vote on anything that affects me?