Why did many workers who worked for successful companies choose not to join labor unions?

In late 1800 many workers joined the labor union because they were not getting enough money to feed their family and pay for food. The workers were only getting $10 a week for all the hard work they do, working 12 hours a day and also putting their lives in danger. This made may workers very angry and thought they deserved a raise. For successful workers who worked in successful companies, there was no need to join the labor unions because they had a relatively good pay.