One thing to keep in mind: with "knowledge work", the work is never done - there's always more to do.
So for middle management it's really hard to measure productivity, so we get this nonsense.
This is also why Agile project management is so popular - it provides a daily metric of what's going on, what people are doing. It forces a granularity of communication (which for those of us with lots to do, gets pretty fucking annoying).