I'm pretty sure those kids have legitimate opinions of their own that they've formulated their whole lives, which were also informed by the murder of their classmates. People don't begin to able to think rationally at 18. Should kids be seen and not heard, like in Victorian times? Being in Florida, my guess is that some of their parents probably had/have a pro-gun stance.
It just seems weird to me that people want to silence these kids. I've heard parts of speeches given by that one girl, I forget her name, and it was really inspiring, extremely coherent, beautiful, really.
When you just saw 17 of your classmates get murdered, and then see the resulting waves made that include all the up to being accused of being crisis actors, I don't think it's time to "sit back and gather opinions and ideas". I think that their entire point is that people have been sitting back for too long.