I get the part about arrogance and looking down on people with less knowledge or skill. There's a certain "macho" aspect to the culture that does bother me.
But I'm baffled by his confusion that people enjoy doing this outside their job. Granted, the passion to create and the enjoyment derived from it isn't shared by everyone, but it's not THAT uncommon - no one bats an eye at artists practicing their craft "in their spare time", or people who enjoy tinkering or building random stuff around the house - again, "in their spare time". It's a craft, and many people who pick up a craft because they enjoy doing it... enjoy doing it.