"We're in a war of ideas. If we intend to change the sick elements of the culture, we have to attack the ideas that are behind them. And to do that, we need to understand why people hold on to bad ideas."

That is the fine beginning to Joe's article.  An excellent article.  Early on, Joe distinguishes between the initial acceptance of a bad idea versus why some bad ideas stand the test of time.

The article goes on to discuss what, in effect, are epistemological and/or practical aspects to some bad ideas that let them continue.  For example, an idea that results in not taking an action means that there will be an absence of negative feedback.  This is based upon the concept that an action which fails can teach.  This is an explanation of how the practice of a given idea can permit it to continue even though it is a bad idea.

Joe's article integrates an understanding of the practice and the epistemology of some bad ideas.  I'd like to point out the existence of a third category of motivations for bad ideas perservering: emotions. 

We think, hence the need for epistemology.  We must act, hence the benefit of examining the practical outcomes of different actions.  But humans can also choose to act based upon emotions and often do so under the coloration of bad ideas.  An unfortunate, but real, aspect of human nature is that we are capable of acting on emotions with a thought process coming along immediately after the emotion and providing rationales, justifications - creating the pretense that the action, and the emotion, were logical.

People can build personalities that are, in part, based upon a collection of related emotional defense mechanisms and just plain flawed forms of thought.  And in this fashion they can collect those bad ideas that lend themselves to this motivation.

This is important to understand since a person who is holding a bad idea for emotional reasons is less likely to respond to arguments that refer to the bad idea's flawed epistemology or to its practical shortcomings.