Of course they do. Because Unions drive competitiveness down, decrease efficiency, increase costs and so on. A lot of people would be very satisfied if they didn't have to work as hard and their paycheck would be pretty effortlessly guaranteed, and competition within the industry was kept in check.
But everybody else have to pay for it . And then naive socialists who advance labor unions forget about it, and start another campaign on why can't blue collar workers afford any white collar services anymore. Why are public teachers collectively not doing great job despite second in the world spending per student. And then riot on the streets why some cops are shooting people for no good reason, after years of people reporting their abuse. (I'm not saying that unions are the only or even main reason, but they sure do contribute to the problem).