As a former LEO I am happy to see constructive common sense approaches to personal safety. I am a big ugly guy, so I am rarely bothered (I am also usually strapped), but I have been put in dicey situations myself. But I am also the father of 2 beautiful teenaged daughters, and now the step father to an equally beautiful 6 year old step daughter.... and I worry. A LOT. The best defense anyone can have situational awareness. I like the fact that this guy's approach seems to stress that. Yes having a knife or a gun is handy, but not fool proof. Just to put it in perspective, the average high school kid can run the 100 yd dash in the 10 second range. That extrapolates to 30 feet in 2 seconds (roughly, the wife is the math teacher not me). So think can you effectively draw a gun (or knife), find a point of aim, and be steady on your sight picture in 2 seconds? I can, but it has taken years of practice.
So do yourself a favor and be aware, that is your best defense. Ride safe and smart.