Even if you post constructive negative feedback on your game's respective forum, the chance of it getting derailed or too flamed, then eventually deleted is quite high. At least in the Feedback Poll things are kept quite civil, doing the same for each individual game would be a good idea, if they actually read and took it into consideration.
The Feedback Poll have been a monthly thing for a long time already, but it's the same issues that have been brought up by a lot of players, every single month. I don't really have any faith that the feedback we write is actually being read.. and if by some chance it does get read, it certainly doesn't have much effect on how they run things here.