That was just an observation I made and it holds true surprisingly often. If you open a game with 100 ratings, you might expect 1000 followers. Give or take.
Seeing a game with 1000 followers and only 10 ratings or a game with 100 ratings and 100 followers would be rather odd.
Maybe you have project where people are excited to hear about completion of the project. But they did not yet play the unfinished version. So they follow, but not rate.