Comment 2 for bug 152228

I understand what IOWait is. And I get that it isn't busy, but waiting. But while it is "busy waiting" (har har), those CPU cycles are lost, and that percentage of the processor is utilized, making the machine slower.

What I'm saying, is that seeing your IOWait is useful. And that with the current color scheme, it looks like your CPU is idle when it is using IOWait. For example, a use case:

Bob, a Windows/.NET developer is using Ubuntu for the first time. He installs MonoDevelop so he can try out .NET on Linux. Bob launches MD from the main menu. He notices that it is taking a while for MD to load, and his HDD sounds busy. He looks at his system monitor to see how busy the machine is. It looks like the cpu is at 2%, but his entire desktop is very slow, even the things that would not touch the HDD.

Because Bob's can't see the difference between #002F3D and #000000, he has a usability problem.