This kind of thing happens a lot. Something "negative" comes up about a popular person and everyone comes crawling out of the wood work about how they "knew all along" and "this person really is such a horrible person" and "on my god how could they do this?"
I'm probably going to regret the few comments I've made in this thread ... but yeah, I really don't think that video was that bad. It shows off how engineering can be applied to defending from possible future attacks. Maybe someone could use this offensively and "promotes the military industrial complex" but I think a bullet or a bomb is a lot more economical than "anvil" and "anvil" is something folks could potentially see in real life in civilian defense applications.
I'd personally love to see more people taking an interest and inspiration from counter weapons systems rather than the mentality of "the best defense is a good offense." Not because I want to see more war, but because I think we've created some really nasty weapons and the shield and castle have long been out classed... People should be able to protect themselves.