One my co workers responded to people going to a union meeting with a derogatory Insult

I just have to say I don’t understand the need for it, join the union or don’t but don’t insult those on the opposing side especially if they’re trying to improve the work place for everyone not just them selves. Needless to say the group of guys he said it were very pissed off at him and straight told him to shut up because he’s talking bs and doesn’t understand the goals of a union.