Sure, most people learn, but what he is saying is that some percentage do not learn and that is enough to allow a security breach. No matter how small a percentage - all it takes is one. We had such a person - time and again they would click on malware links, after warnings, explanations, etc. One day their spouse emailed them saying there was thus and such a phishing email out and not to click on it (I guess this happened at home as well), and still they clicked on it. Fortunately, they left to plague some other company when they were pressured too much. Sure, an egregious example, but there is always someone that makes this mistake.
And, yes, Snowden is a patriot.