This makes two big assumptions that can't be overlooked:
1. People can't self-manage (to some degree)
2. Performance is the end goal of management
I think both of these are wrong, or at least unfounded. I work in a more-or-less self-managed environment, and performance is actually pretty good. I get to pursue about 50% of my work independently and the other half is either collaborative and in line with a coworker's needs, or is one of those "must-dos". I don't see a possible world where I'd get more work done over the average day if there were artificial metrics like "time spent at desk", "lines of code written" or "number of tasks completed" dangled over my head - I'd probably just fuck off more and come up with clever schemes to break the game. This problem can be seen in academia as well - give a bunch of smart people a matrix of rules and yell "GO!". Watch them optimize.
I'd also argue that if it's only performance you're looking for, you're both ethically and intellectually off base. Good managers do increase performance/productivity - bad managers do not. But to assume that, as with teachers, academics, or software engineers, you can measure and reward behaviors without causing adverse affects on your workplace then you're dreaming. My manager is good because he backs off when needed, leaving me and a coworker to argue about an implementation design. My manager is good because he sets up an area of focus and says "ideas, go!". My manager is good because he will let people take a week or month to pursue a new solution that he personally doesn't understand, but trusts them to solve it aptly. My manager is not good because his team excels in certain metrics - his team excels in certain metrics because he is good. And last, my manager is good because productivity is not the end goal - employee happiness is. Happy employees do good work, and more importantly, they're happy for their own sake, which is much better than being surrounded by burnt out metric junkies.
So maybe my takeaway is that if we're going to do any kind of metric gathering it should probably be sub-perceptible and not be treated as a golden calf. If my CEO wants to devise a clever way of using me as a science experiment in pursuit of better management practices then I encourage that. But to tell people "here's what we're tracking now go off and do good work instead of that" is really fraught with problems.