Common Sense. Simple Common Sense.
It’s interesting how the Windows UI has gotten more bright an colorful as time has gone on. The OSX User Interface on the other hand, is almost entirely grey now, save application icons.
If your job required you to listen all day long, would you prefer a system that was loud all the time, or a system that was quiet all the time, only making noise when required?
I spend my life struggling with “enterprise-class” software UIs. If the Windows Explorer UI was the worst I ever had to deal with, my professional life would be practically trouble-free.