The ports were closed because of management trying to undermine the workers. It's in the same article. So it does go back to capitalist social relations no matter how you look at it. It was the bosses that closed the ports completely to try and break the bargaining power of the workers. Basically to use force to keep the workers doing more than their contract actually calls for them to do. The workers just worked slowly (and in accordance with their job descriptions, which is why they weren't just fired), it was the bosses that childishly and derailed the entire port system by closing it down - effectively holding everyone to ransom and blaming the workers.
Ports from San Diego to Seattle were all but shut down several months ago as the two sides haggled. Companies that accused workers of coordinated slowdowns decided to cut their shifts, shuttering ports on nights and weekends.
"Slowdowns" are a tactic where you work to what you're
actually paid to do. Bosses cannot fire you because usually it means doing thing "by the book". It's also known a "work to rule": i.e. workers start following the actual rules rather than taking initiative, and this actually cripples production. It's a way of highlighting to management how much exta you're actually doing - extra things that you should really be paid for.
http://en.wikipedia.org/wiki/Work-to-ruleWork-to-rule is an industrial action in which employees do no more than the minimum required by the rules of their contract, and precisely follow safety or other regulations in order to cause a slowdown, rather than to serve their purposes.[1][2] Such an action is considered less disruptive than a strike or lockout; and just obeying the rules is less susceptible to disciplinary action.
No capitalist entity should do "more than the minimum required by the rules of their contract" so why should workers be shamed for no doing extra? You want extra, pay for extra. That's how capitalism works. There shouldn't be one set of capitalist rules for the bosses, yet if a worker doesn't break his own back as a docile slave, they get shamed for their bad attitude.
Objectivism/Libertarianism states that each economic entity must be driven by rational self interest, and that self-interest is the highest morality. But this can't just apply to just bosses, if self-interest is a universal ethic as objectivists claim, then greedy workers must be the best workers.