Well, I think that 50 years ago they were relevant, but now all I have to do is think about the airline industry and their unions and I get angry (I used to work at United, and had to negotiate on the flight attendant contracts regularly, they were ridiculous! Not to mention that we got stuck in LA for the first two days of our honeymoon due to a ramp workers dispute over contracts.) I just don't see why certain careers need unions, while others do not. Should doctors form a union?
Also, I worked as a grocery cashier when I was in high school and was forced to join the union there. The only thing that I ever got out of it was a pin (which we were also forced to wear). I never even got a copy of the union contract, or newsletters or anything, just a deduction from my paycheck.