Why is the sin nature inherited?

[Cinjin]

I've been doing better lately - not bothering with these sort of posts, but sometimes I just get it under my skin and I have to let it fly.

Eating of the tree of knoweledge seperated man from God. So God gave man over (completely) to his desision to be seperated from Him.

But it was always a Catch 22. Pretending for a moment that the story isn't fictional ...

Even if Adam and Eve hadn't taken a bite of the forbidden fruit, and Cain hadn't killed his brother, eventually some hungry fuck would've come along and screwed it all up. Clearly, mankind was always MEANT to fall, and that therein lies the absurdity of the story.

god created Adam and Eve
god created the tree
god created the fruit
god created the "no-eaty" rule
...and in doing so, god created sin.

There was only one reason to create the tree and make an anti-fruit rule: god HAD to make man fall ... for what reason? Who the fuck knows. Sadism maybe?
No tree = no fruit. No fruit = no rule. No rule = no sin. No sin = no fall.
I mean honestly, how do people not see this? The story does not hold up and even if it did, god would only have himself to blame.

I mean christ! No wonder Lucifer bailed. He was probably thinking to himself, "wow, this god guy is one seriously delusional asshole and may even have a healthy bi-polar disorder."