I think his point is that "old people" won't live with the outcome of their votes. It's not a generally correct point, but it makes sense from the perspective that they don't have skin in the game.
Are they malicious? Maybe, maybe not. But at the end of the day it doesn't matter if they're malicious, senile, or just plain old apathetic.
(Perhaps you can find a political issue for which young people throw caution to the wind and old people exercise appropriate caution, but I can guarantee you that the impact of that issue will not be as severe as climate change.)
"We don't think they vote the right way, so we should deny them the right to vote" is a really shaky moral foundation for actions that rapidly destroy democracy.
And you don't like it when the other side does it...
If democracy needs to be temporarily compromised to save the planet, so be it. The dogma of universal suffrage should not be our top priority (not that we currently live by it anyway!)
You are willing to "temporarily compromise" democracy. I doubt that it would be temporary; I doubt that it would be merely "compromise"; and I do not join you.
Most past seemingly good reasons to temporarily compromise democracy turned out in hindsight to not be worth it. This one might be actually worth it, or maybe the next once will, but we're generally well served by a taboo against dismantling democracy.
A revolution could well not go the way you want, and end up in a system where no one can even defend fighting climate change, or worse, everyone has to enthusiastically pretend we're doing a heroic effort that is well on track to solve the problem.
Yeah. The one who winds up in power is whoever is best at using the situation to take power. This does not have any correlation with who is best at actually solving the problem.
It's almost like black and white statements are just bad stereotypes.