The only thing wrong with incest is the child. We put a lot of focus on this but not other kinds of ‘bad’ genes like hereditary diseases.

To me taboos is just society taking shortcuts. This is fine, but lets admit that we are taking shortcuts.

In reality there's often issues of manipulation into "consent".

And if the relationship goes bad you lose a family member, not just a lover.

Is it always wrong? To me, unquestionably no (consider my example.) Is it risky? Yes.

I'd agree- I think the analysis I was referring to believed that analyzing a taboo makes it no longer useful as a shortcut. Guess that didn't come across enough for anyone to offer a refutation.