What a bizarre bait and switch. Starts talking about browsers allowing malformed HTML and uses that to draw conclusions about allowing certain types of people.
It's a poor metaphor. Real tolerance necessitates intolerance - see Marcuse. What is a browser going to do, send malformed HTTP requests and name-and-shame any server who refuses to respond? Servers vs. browsers is not the same type of relationship as people vs. people.
Not to mention that the author's metaphor is implying that certain types of people are malformed.
