it's really neither about being pro-partying or anti-partying, so much as it is about mocking crusty conservative portrayals of the corruption of the youth. the video really represents what some reagan conservative might have imagined a party of young people was like, but hardly actually existed in real life.
this is a problem i've run into with the songs i wrote when i was young, as well - sometimes you intend to get across an idea, and don't get it across the way you want to, leading to confusion or ambiguity. it seems to be common for people to accuse each other of misunderstanding the song; i'm going to place the blame on the band. it's legitimately not clear what they're trying to get across, as they were certainly neither advocates of absurd behaviour as portrayed in the video, nor of the kind of conservative value systems that would shut it down. the subtlety has maybe been lost in time.
so, it's absurdist humour, but it's making a serious point, too. the mockery is more reflective of perceptions people had in the 80s surrounding the difference between "good" and "bad" people; while such parties probably existed nowhere on the actual planet, it's a reasonable reflection of how you would hear older people talk about younger people, and the corruption of the youth and whatnot. you do need to fight for your rights to free expression, or you will lose them, as much fun as it is to be silly about conservative portrayals of the lifestyles of the young.
"it's 11:00 pm. do you know where your children are?"
they're probably not quite doing what you see in the video, but maybe you imagine they are. that's the joke, here.
in context, the most facile interpretation is the most relevant one - they're coming for you, and you'd better stand up, or face the consequences for you and your children, and your children's children.