You're severely underestimating the kids. Please, ask yourself what is more likely: that there was a legitimate buildup to this moment after years of gun violence in schools reaching a tipping point, or that these kids are all props for someone's political agenda? MFOL was organized by a variety of people, but it has real roots dating back years and should be viewed as an organic movement.
The march took place during what is spring break for a lot of kids. You're blind if you think people would organize one of the largest protests ever just to get out of school for one day. There was a lot of hurt in those speeches from the kids, you could trace where it's coming from too.
I said it on the other site (rip), but I expect nothing meaningful on gun reform to happen in the near future. Also I never advocated for repealing the 2nd, so idk who you're arguing with. There's a significant number of people arguing for some reform, and I think it's wise to listen and to understand where they're coming from.