Strengthening the ties between existing Itch devs, and making it more rewarding for people to be part of Itch would be good ideas but difficult to do. All game developers want critique and publicity but rarely have time/ motivation to help others with these, which is why the 'Get Feedback' forum is so unresponsive.
Perhaps making it easier to exchange reviews and feedback would be a good idea or promoting users who give back to the community like this. Personally, I enjoy critiquing other people's games, but there doesn't seem to be too much reward for doing this, especially when developing takes up so much of your spare time.
There was an attempt a few months ago to get a group to pick a game from the group every week and give feedback on it. This was moderately succesful (and I reviewed one or two), but the OP stopped and no-one took over- the threads also had to be shoehorned fairly awkwardly into the forums. It would be good if some kind of similar system could be incorporated into Itch.
Or maybe list the top reviewers every month (based on some combination of quantity, positive reactions to their reviews, and subjective assessment) and hope people's competitiveness helps improve the Itch community.