A fair question, by any measure. Actually, to me, that is what sucks the most about the whole thing, after the dead and injured. Personally, I don't want to see the kid go to prison for the rest of his life. I hope he doesn't.
However, I do feel Rittenhouse is the cause of these events. I do think a message needs to be sent that what he did is not okay. I think the trial is a defining moment for this country. And I will choose the message of "You don't get to play vigilante or hunt protestors", over, "Come on down, militia dudes, and try your luck at the protestor shooting range! It's open season!".
And, let's be honest: That second part DOES appeal to a lot of people. Even if they don't do it themselves.