Pete Seeger has spent his life singing things which were not (at that time) PC... Woody Guthrie did a lot (but not all) the same. Arlo doesn't follow those antecedents,however...
As they say, it used to be I dint no how to spel ingineer & now I ar one.
My father was an engineer, I am an engineer, none of my three sisters wished to be one. My daughter doesn't wish to be one, but my son wants MAYBE to be a scientist. An Engineer, for those who don't know, is one who applies in the real world, what the scientists find out in theory. One of my first bosses was a female engineer, who transferred from the Structural Dept to Civil Dept because the head of Structures didn't seem to think (it was reported) that a woman could do it. She was one of the best bosses and one of the best engineers I've ever worked with or for in the last 30 years or so.
I have to admit, however, that I have never heard a really good PC song. You have to have a point, something to focus your attention and the lyrics (and subsequently the music) on to keep the attention of the people who listen to it and may sing it or buy it. Therefore, except for the True Love and Love Lost routines, most songwriters will need to be non-PC, if only slightly, for the course of the song -- whether they actually feel that way in real life or not is immaterial. If it weren't for non-PC lyrics, you never would have had a lot of Joyce Kilmer's poetry, none of Service's "Rhymes of a Red Cross Man", etc. from WWI, etc. You wouldn't have had the protest songs of the 60's, and we'd ALL be "Blowin' in the Wind"
However, there are notable exceptions to this, such as Ralph McTell's "Streets of London", although some references in the song may be "something we just don't talk about" as one aunt once said, it was well said and not offensive, because it reflected real life.
Real life is not PC, and, as Steve Goodman said in his song of the same name, you have to "Read in between the lines"