This can actually decrease productivity due to frustration when the EE's realize they have been deceived into thinking their opinions matter. It's subjective not objective. It is based on opinions not behaviors. Popularity is not performance. Opinions are not business results.
Opinions serve as a poor substitute for real performance data.
Most EE's don't see the big picture so their feedback is based on minutia and gives no real insight into strategic issues. Anonymous processes short circuit the need to develop 1 on 1 communication skills and the ability to provide negative feedback. It is a slow and time consuming process. Respondents are slow to fill out the forms and a skewed response occurs when only the unhappy respond. Anonymity does not allow for encouraging individual non-respondents to participate, resulting in a low response rate.