Back when I was in college, you could take month-long classes between semesters. They were generally the younger professors' only chance to use their imaginations in course creation. It tended that the more "fru-fru" the class, the more work was actually involved. The course description might make it seem like you're watching a movie every day in class, but it didn't mention that you had to write a paper about each movie.

One class I didn't take, but wish I had, was on the Geography of Food. Why places have different food cultures, that sort of thing. Of course, maybe if I had taken the class I wouldn't be so interested in it today.

 "Can Nietzsche's rejection of traditional morality justify Bart's bad behavior?"

Short answer: 'no'. 

Long answer:

If one accepts that Bart isfundamentallynihilistic then maybe - but then, as a 'child' wouldn't that be expected - at least to a degree?

If so, then Lisa counterpoints with more enlightenment, idealism - and [occasionally] refreshing cynicism. Homer and Marge represent their 'role' models, respectively. Maggie, perhaps more of a blank canvas, exhibits both - sometimes in unexpected ways.

If we believe the Simpsons is an allegory for contempory American society (and not just America), then Bart's behaviouris justified if only because contemporary America has deemed it so. If wedon't then perhaps he's just a character in a satirical cartoon show.

It's amusing perhaps because it hits close to home. It forces us to laugh at some aspects of our own nature we may not otherwise be comfortable with, were they subject to more 'objective' scrutiny.

If [many] people didn't [even on a subconcious level] aspire to emulate some of Bart/Homer's disregard for convention then it would have no resonance. The same could be said of Lisa/Marge's aim to 'do the right thing'. Perhaps Mr. Burns represents some derivative of an Orwellian state ... and so on!

Homer's behaviour is excused because he's [portrayed as] an idiot, Bart because he's a nihilistic child who emulates his Father. Marge because she's [portrayed as] intelligent but frustrated with many aspects of her life, perhaps rueing some of the choices she made along the way. Lisa because she's an idealistic child who emulates her Mother.

It's also true that that blamingpoliticians and legislation (while certainly a factor) is a convenient vehicle to avoid individual responsibility for what we collectively dislike about contempory society. After all, it's much rarer to heap praise on official organs for the things we dolike, isn't it we tend to reserve that accolade unto ourselves, so one might ask ... why is that?