Yes it was. God didn’t want people to live forever in their fallen state. The Nephilim may have thought they would live forever, in their fallen state too, but God made short work of them, with the Flood. Can you imagine these hideous, infernal cretins, harassing Noah for 120 years, while he was building the ark? I imagine, that as the rain stated falling, something that I don’t think ever happened before, those slime bags were telling Noah to let them on the ark. Noah was probably saying, where were you for the last 120 years, as I preached repentance to you? God’s judgment never comes, without a warning(s) but when it comes, it is swift, terrible, permanent, and seems to catch them completely by surprise.
And they were probably cursing God while it happened.
Just like Revelation says people will do when God’s judgments fall on them.
And they can’t say they weren’t warned.