IMO if there's enough busywaiting that it shows up on the CPU load, then there's so much busywaiting that that is a problem, because a CPU that's busy with such chores is not available for real work. The CPU load is not (as you say) very lucid, a bit like the question mark in the "unix car" joke, but in that particular case it's caused by a real problem: Too much busywaiting.
