Since I've been in the forums since dirt was the next new thing, I've followed the progression. First thing everyone wanted was round ATA cables to "improve aiflow" because the cable laying across the air pathway was bad. I pointed out that I liked to fold my flat cables up against the drive cage, and suddenly I was enemy #1.
About the same time people started talking about sleeves for power cables to keep them from getting tangled. Of course those had to be round too.
Then a non-manufacturer...I think maybe it was Ultra (Tigerdirect's brand), started ordering power supplies with ribbon cables. Oh, they were sooooo soft and flexible. Some people noticed that they were easier to install. Others noticed they weren't round.
If people could only begin to make logical choices about these things we wouldn't be taking this step backwards with individually sleeved wires, and we would have super-flexible power ribbons.