It is certainly immature and shows bad judgement, then again, so do door and yard signs that say "property protected by glock," or "my rottweiler makes it to the fence in 2.8 seconds. Can you?" It doesn't show people want to shoot people, or people want their dogs to attack people. It is just immature humor that douchebag think is cool or funny. Unfortunately this type of thing gets released to the masses and then everyone wants to light a torch and lynch someone, despite it having nothing to do with anything. As history has shown, many people are overly emotional, and lack rationality.
I haven't watched the video, btw (and wont), but in reading through the thread this engraving stood out to me as wtf is that even mentioned. I guess media is gunna media though. News stations probably had panels and debates over this specifically, lol.