I definately think that this is a case where some of the individuals working may not be as good as others, and even if you have no plan on returning to DCL it would benefit others to make a complaint. I have always found Disney to take complaints seriously, and how can they fix something if they don't know about it? Just wanted to encourage you let Disney know (you may even get something for it!)
Like I stated above, this is not a problem of DCL being unaware of one or two problematic counselors or a particular incident that happened. The problem lies in DCL's employment practices, the way they have chosen to structure the kids club, and the amount of resources (or lack thereof) they have chosen to dedicate to quality childcare.
DCL has made a conscious decision to make things the way they are and they are well aware of the consequences of these decisions. And to be honest, based on some of the responses to this thread and what we observed from many of the parents on our cruise, most people don't really care about these shortcomings, so DCL has no motivation to improve.
When I filled out the comment card at the end of the cruise, I made it obvious that everything other than the childcare was great and that the childcare soured our overall experience and we are very unlikely to book DCL in the future as a result. Obviously this was enough to trigger a mandatory follow up phone call, but I wouldn't expect any meaningful changes from DCL until massive numbers of parents lodge similar complaints. In the end, DCL only cares how people vote with their wallets.