I think I've only received one such survey in the past two years. I love to give honest feedback (good and bad) on these things. I wish I get them after every stay.
One problem with the surveys is that I seem to get them about two weeks after the stay. By then, I've usually stayed at a couple other hotels, and I can't recall most of the details from the stay they ask about. How the heck am I going to remember the condition of the drapes and carpeting?
Attention ICG survey creators: please send more surveys, and send them within two or three days after the stay.