It may sound simplistic but its the truth and there are plenty of other examples and history around this - Starbucks recently. 30 employees unionizing may not have any significant impact on their profits, but if they let that union grow it would have a lot more members demanding better working hours or wages over time. A strong union also generally leads to a loss of control by management where they have to negotiate more with workers which they don't like. Why do you think they were fired?