Dunno what kind of lousy shops you worked at but nobody ever did anything like that at the granite shop I worked at for 5 years, nobody did that kind of stuff in the landscaping crews I worked on.
And even though I felt my coworkers were somewhat OK, they would still make remarks (especially homophobic & racist ones) that would be at least grounds for disciplinary action in most white collar fields.
That (along with RSI and the pay) was one of the reasons I left the trade. I enjoyed the job, it is really satisfying to have that sense of accomplishment at the end of the day, but I was frankly tired of having to be around/associated with crappy people.
those guys smoke, sit in the sun all day, work with all kinds of toxic shit, can fall, and don't have huge career growth potential.
they have nothing to lose and the humor shows it