I wish the article had explained that overcrowding is the result of giving out club passes by the millions as an incentive to open United credit card accounts. Those credit cards earn United hundreds of millions of dollars, at least some of which is attributable to the club passes.
In essence, United oversold its club seating. Its solution was involuntary denied boarding for lifetime members with no compensation.
They definitely oversold their club seating, and decided people flying their competitors were the lowest priority. That is the the precise explanation for this.
Still it is a crappy way of doing business.