To me limiting the number of devices to 12 -- receptacles or lights or a combination of both on 15a general circuits--- makes logical sense --- 80% .
Nothing prohibits that number of devices from being in one room. If you want to cram 12 receptacles into an average bedroom no problem. Just means that bedroom is on it's own circuit --- which isn't necessarily a bad thing.

But by placing a limit on the amount of outlets you might introduce those cheap Dollar Store extension cords to provide power for devices not intended.
Speaking of .....
I shake my head when seeing power bars stuffed with cords even with power bars feeding other power bars stuffed with cords.

I remember as a young lad the public service ads warning of the nasty electrical " octopus " showing cords crammed into the old cheaters being a fire hazard ---- which they are.
But yet today there isn't a second thought of having power bars strewn about every home crammed with cords ---- me thinks same animal just different shape and color.