I came here to say this but since you've already said it, I'll also provide an on-the-other-hand!

On the other hand, CPU utilisation is used to scale CPU frequency on some systems. This generally works OK but if a workload is spending most of its time blocking on the memory subsystem then scaling up the CPU frequency might (depending on the HW architecture) not actually speed it up at all, but just waste power. In that case the perf counters mentioned in the article might be a better metric for freq scaling. I think Intel CPUs usually do this already but not exactly sure.

So yeah basically the utilisation metric isn't "wrong", you just have to understand what it actually means before using it.