I agree that children shouldn't worry about the future. But in this case, it's hard to ignore, if you can see it all around you.
I grew up on a farm. That's great, as a kid. Lots of room, animals, always activity to participate in.
I can remember being four years old and being led around the pasture by my grandfather, who died when I was six. Even then, the signs we were ruining this earth were showing. He explained, for instance, that there was far too much concrete in the world. Rainwater doesn't get a chance to go into the earth. In stead, it is tubed directly to the river.
Fast forward half a century. I was working for a water treatment company. One of the biggest in the world. I got to see historical data of the underground water line. At that moment, it was some 3,5 meters below average. That's 15 years ago. Today, the level is at -5,5 meters.
It reminded me of what my grandfather was telling me.
It's not new. Plastic didn't appear in our environment in a few years. It's been going on for decades. That makes it easy for some to ignore.
These kids aren't being led. They can see with their own eyes what the world has become. The saddest thing is that people who have seen the evolution, deny it. And that's why these kids act.
It is obscene that some can deny these kids have eyes and can see what's going on. It's also a sign why we, as the older generation, are unable to solve anything, as we can always ignore it and blame it on the other side, whichever side we're on...