If you do this, you should probably avoid the 5-star iconography altogether, since at this point, it's too ingrained in our collective mind that anything below

If you do this, you should probably avoid the 5-star iconography altogether, since at this point, it's too ingrained in our collective mind that anything below 4.5 stars is crap. A good representation for the rating system you describe (where every active install counts as a weak neutral review) would be a like/dislike bar, where the neutral position looks like ----------|---------- and a really good app has a green bar like ----------=======|--- whereas a bad app has a red bar like ------|====----------