how is this even debatable

is it actually against the law ?

Think it might has something to do with academic theory which exceeds mental utilization and understanding. That and most people haven't evolved beyond acting impulsively. This is largely due to the greed of our corporate societies and the possessive nature which they instill. Les Miserables "1935" illustrates this concept gracefully.
If you enjoy old classics give it a watch. It's on Netflix.

It doesn't contain any incest per se but a few scenes could serve to illustrate moral lessons about incest.
Parental and sibling relations shouldn't be incestuous sexploitation. Rather such relationships should be a source of generosity and protection.

Yes, the source of incestuous desire is corporate greed.

It's greed and selfishness in general. But it is corporatism which serves as a supreme influence introducing those values socially.
Family bonds mean less than ever to the modern corporate society. Family members simply become capital to exploit for our needs.
The association is obvious even if you prescribe yourself to avoiding its witness.

Because incest is a new thing.

Hell, I'd wager incest has dropped drastically in prevalence in modern times. It's an extremely common recurring theme throughout history, especially among royalty.

Makes sense that it has dropped down in modern times with our understanding of genetics. But so have many other greedy and selfish behaviors given our increased understanding.
Royalty did this in attempt to concentrate power without such understanding. Monarchies are simply a primitive form of government; which corporatism has replaced when you get down to it. Most people have outgrown being governed by tyrants to only become tyrants themselves.
You're only proving my point for me. Thanks I guess. Have you ever watched the movie I suggested?

This post was edited by TradeBot on Jul 13 2014 09:23pm

You make your case and I'll make a case opposed to it.