They plan to impede on the education of children for the sake of political gain. 

Via USA Today: 

After the Santa Fe and Parkland school shootings, parents need to draw the line. We can make Congress pay attention by keeping our kids at home.

What would happen if millions of parents across America kept their kids out of school for a few days this fall to put pressure on Congress to pass gun safety laws? With the midterm elections coming and control of Congress hanging in the balance, would our politicians finally do something about the mass shootings in schools and other public places?

Maybe we should find out.

Read more here.