I feel that it's because people are more prone to complain than compliment. If you take a random survey of the threads on this forum, you'll probably find twice as many people complaining about something, than those who compliment or praise something.
Those people who are dealing with CW don't fall into a "Black Hole", they just have their problem solved, and forget about it.....and it's up to them, to let us know what happens.
I guess CW could have someone who writes a note telling you what they did, but then it seems as if they are patting themselves on the back, and someone would probably complain:)