None of that has even the slightest bearing on why the guy is intentionally blowing up civilians at a footrace. I repeat, I don't criticize all violent resistance against the government ... I criticize the guy who is *blowing up civilians at a footrace.* It's no defense to say "Hitler was even MORE evil." Well, yeah, I get that Hitler might be more evil on balance, that still doesn't allow you to walk around shooting 8 year olds in the head. When we drop a bomb in Afghanistan, it doesn't then mean you are cleared to start spiking your neighborhood's pet dogs in the head with a pickaxe, just because that's a hell of a lot easier than actually going after the people at fault -- people who tend to have guns and are able to defend themselves.
So if this guy was attacking soldiers or trying to blow up Congress, I could get your point. But he's not. He's trying to slaughter the most hapless civilians he can find because he knows he can't do anything against the ACTUAL powers that be. Instead he wants to blow up a bunch of people running in a footrace, in order to terrorize the populace. This will always be one of the lowest and most disgusting kinds of violence imaginable. It doesn't matter why you are doing it.