thirlwell is shock rock; that tune was a little more offensive than i remembered it, so i feel the need to write this.
he's in character. you're not supposed to identify with it, so much as you're supposed to interpret it as a character attached to the music. and, this is often the case with thirlwell, who writes a lot of music that has felt rather exotic in the last quarter of the twentieth century, and the first quarter of this one. he doesn't just put it out there, he narrates it from this historical understanding of it, helping you see it from that first-person perspective, rather than just interpreting it as a product of a distant culture.
swing music was all about male energy and macho swagger on the floor. there's a kind of revisionist slant on this. and, women were more free in the 20s and 30s than they were immediately after the war, too, remember, when this kind of insular conservatism set in as a reaction to the depravity of what had just happened - and the promiscuity inherent to years away from your partner. so, a swing party was hunting grounds for consensual encounters. and, that's what he's trying to get across - without revisionist filters.
is he a historian, then? i dunno. but, it's a kind of satire, with it's wry humour, as it narrates that history.
and it's agit-prop.
so, i'm consequently not going to argue with you if you find his work offensive; his work is offensive, and you're supposed to be offended by it. he agrees it's offensive. but, then you're supposed to do something about it, or reflect on it, or just call it what it is.
you're not supposed to just tell him to stop offending you; that's not activism, it's a reactionary type of conservatism. activists dismantle things, they don't censor them.
personally? i'm going to agree he goes a little overboard. the "sister could you spare a suck?" part was a little gauche. now, as mentioned, you could and probably should make the opposite argument - that to be an authentic expression of the character of a swing dancer, you need to be crass like that. but, that doesn't mean it's enjoyable to listen to as music. so, what you end up doing is kind of overlooking these kinds of moments.
but, there's an argument that thirlwell realized that, too - the track was released as a side project on a small label. it's been out of print for years. you'll never find it for sale anywhere. if he had confidence in the presentation, he would have put it on an album....
in later years, thirlwell would seem to present the perspective that he got to a point where he was sick of people reacting negatively to what he was doing and stepped away from doing it. it's hard to blame him for giving up. but, he was really misunderstood from the start.