I think you mean that it is not because people are less intelligent. They are definitely stupider.
The American Revolution was a giant step away from the tyranny of monarchy, in great part due to the size of the Atlantic Ocean. The fact that the Revolution did not solve all social injustices is hardly justification for today's under-informed youth to reject it.
It took about ninety years for the majority of Americans to support taking up arms to kill Southerners, resulting in the end of slavery.
It's been thirty years since Kalifornia made it a felony for me to put a plastic pistol grip on my rifle. It's still illegal.
You are correct, I was imprecise.