I know very little about unions but I feel like it is a dirty word. A very "us versus them" type of idea.
Companies don't start out wanting to mistreat people. Companies grow in the market they are in, and the conditions are set by their competitors.
Standing up for "I want to work less, make more, get better benefits" just isn't competitive if your competitor isn't doing it.
Strong-arming your employer almost never seems like a good idea.