While I think what the union does for contract towers is minimal, they definitely help. According to one of the people I worked with before I got there, Midwest ATC was having controllers work past the closing time of the airport for free to finish up the logs, do traffic count, and whatever else. NATCA got that changed and got the controllers paid for that time. I feel like this should have been a violation of state/federal law regardless but I could have the details messed up since its been awhile.
Most FAA controllers that think NATCA shouldn't help contract towers are mad about their seniority time. I paid my dues at my contract tower and in the FAA. If you want to make the argument that contract tower time shouldn't count then maybe your time shouldn't count when you transfer facilities. Stop letting high seniority people transfer and jump everyone right? I mean they paid their dues too but fuck em it doesn't benefit me.
Contract towers that join the union and people somehow get their seniority bumped up after the fact is lame though.