The Creator forbade His angels from helping the fallen mankind, an order which some of them disobeyed resulting in the Watchers. Given what happened to the Earth after they intervened, the Creator's orders indicate He had already foreseen how screwed up mankind would become when given knowledge and tools and let loose without any sense of morality, which is why he forbade them in the first place.
Moreover, the opening text specifically said that Cain's descendants built an industrial civilization. It never said anything about them also discovering agriculture. So it's hardly a surprise that the Cainites rapidly exhausted the world's plant and animal life, if they weren't raising any of their own crops or livestock.
The fact that God's only referred to as the creator. A mere artistic change, or a nod to the fact that in the Hebrew texts, God's (or Yahweh's) name is never spoken aloud?
Possibly even a nod to the fact that, at this point, creating things is God's only benevolent miracle. It'll take a few more Bible verses until He actually starts decreeing guidelines, answering prayers, and demanding specific rites of worship, or offers a covenant to Abraham.
You do realize Japheth is going to have to fuck one of his own nieces, right?
Presumably so is Ham, if he comes back.
Hey, remember that the entire human race before was produce by Adam and Eve..with no other woman or man. So it was already incest to begin with.
Who did Cain marry?
His twin sister Aclima, according to the Midrash and Islamic sources.
His sister or his mother.
This was totally acceptable at that point, believe it or not. Incest was not specifically forbidden until the book of Leviticus and not widely accepted until around the time of Abraham.
Ila is incredibly lucky that she was wounded as a child and left barren. If she hadn't been, Noah very likely would have thrown her off the Ark and left her to die in the flood.
All the cannibalism and rape and brutality going on in Tubal-Cain's camp? That's what was happening among the strongest remaining human city's refugees, who'd lived close by enough to follow the birds to the Ark construction-site. For those dying cities that were too far away for the inhabitants to reach Noah's forest, their populations had probably already fought and ravished and eaten each other into extinction by the time the Flood struck.
Cain the first farmer killed Abel the first shepherd because Abel was rewarded when he offered God meat. Then why did Cainites follow the creed of Real Men Eat Meat?
Spite? "Oh, so it's meat you like, eh? Well fine then, meat's not ON the menu; meat IS the menu!"
Because they ("they" being the writers) wanted to portray evil meat eaters versus good vegetarians, despite it not being true to the Biblical story. Presuming they even knew that; a lot of people don't realize Cain was the farmer and Abel the meat eater and think it's the other way around.
Or because the Cainites were eating meat but not offering God His share.
According to the Bible, God took agriculture away from Cain after the murder of Abel, in Genesis 4:11-12:
And so, cursed shall you be by the soil that gaped with its mouth to take your brother's blood from your hand.
If you till the soil, it will no longer give you strength. A restless wanderer shall you be on the earth.
Why the hell did Noah still let his sons board the ark if he wants to ensure his clan will die too?
Probably needs them to help deal with all the work of unloading the animals after the flood.
He wanted them to live out their lives and not die horribly like the rest of mankind.
Cain's civilization is described as somewhat industrialized and powered by fossil fuel yet are shown to be at best post-crusade. Tubal-Cain could have built a steampunk ark of his own instead of attacking Noah's!
Yes, but that's not what a man like Tubal-Cain would do. It's seemed easier and faster to take Noah's ark rather than building his own ark.
Where did that pride of their industry go? They've got iron, more manpower, and the trees are up for grabs.
It took Noah an appreciable amount of time to make his with the help of magic angel rock lords, so maybe by the time that Cain's folks decided to take the flood seriously, they had the tools and supplies but simply not the time.
More importantly, they didn't have time or resources sufficient to build enough Arks to accommodate their own numbers. Tubal-Cain's not an idiot; he surely realized that if they built an Ark, his fellow-Cainites would immediately start fighting each other for possession of it, so if there's going to be a battle anyway then they might as well skip the drudgery of construction-work.