Hypothetically, if one of the kids you train shared the same views as Kaepernick, would you also wish him physical harm and the end of his career? What about a family member or friend? 
If one of my kids was in the NFL getting paid $19mil a season and basically said he was a communist and traitor to the country and capitalism that afforded him that $19mil a year, you bet your ass I would. But since these are high school kids, they can voice their opinions without any backlash from me or the rest of the coaching staff. These are kids and as naive as Kaepernick is, he's grown ass man.
You'd be hard pressed to find a HS coach that would disagree