Sorry to hear that. It's possible there's just not much in the corpus that matches your interests. Re: the algorithm, it should start improving faster soon. I'm in the middle of a large refactoring, and I've recently been joined by someone who will work solely on the algorithm after that. (I'm spread pretty thin myself).
FWIW the average rating is 2.5, which does seem kind of low, but still indicates that you're probably an outlier. That being said I've been relying mainly on regular newsletter engagement metrics to judge how effective the recommendations are, since rating can be a little unreliable (people are more likely to rate something when they've had a bad experience). Lately we've been at 46% open rate and 16% click-through rate.