I'll take this as a compliment.

But nah, I ain't shytting on the past.
The past laid the platform for what the game is today, and the past didn't know or had to defend anything else besides what was in front of them. It's not the fact it was necessarily bad defense, it's just that defense mirrored the offense. Defenses back then didn't need to run out and cover the 3-pt line, they didn't need to switch endlessly and communicate through all the screens, they didn't need to watch that big rolling out behind the arc, they didn't need to recover to spaces beyond a few strides.
As someone said above, it's complex why the scoring is what it is today. It's not just one particular thing, and it most certainly is not because the game is watered down or no defense is played like cats are stating or alluding to.