Dumb ass kid had his politics used against him to get him to give up a day off.

Labor day wasn't a communist holiday. At the time labor day was created as a federal holiday, the labor unions were voluntary association. You could work in union shops without joining. There might even be competing unions at your work for you to pick from already.

In fact, many anarchists believe that the historical model of unions from that time is the free and voluntary association way of accomplishing many of the protections for workers that the legal system attempts to provide today.

Anarchists being pro union would not have seemed strange to people of that time. 2 dates were considered for the holiday, one in may and one in September. Both were considered because they were planned recurring strike days by the unions. May had more history of the strike becoming violent, while September tended to be cookouts. The government chose September because they were worried the historically more violent day would become about the anarchist movement.

But the socialists you say. That word has changed. Today socialism basically means government enforced, aka communism. Earlier, there were competing definitions. Socialism often meant that the workers of the business held shared ownership of the business, instead of a single owner hiring workers. This was still a profit seeking business with no government involvement under that model.

Look up anarcho-syndicalism for more about how unions work under anarchy. Look up libertarian socialism for more about how a socialist business can be a free thing that doesn't use government force to achieve its goals. They aren't perfect ideologies, but their ideas hold important truths if people want to be free.

Early model unions and libertarian socialism are both powerful answers to "without a government some other bully will come along and exploit people even worse." I don't think it is a coincidence that those words have become corrupted and earlier meanings lost to time.