Game jams is NOT about ME it about US. The idea that you can just play, rate and give feedback other people games was once right, but can clearly see that this not happening very much any more. The main issue here is 'Rate for rate'-posts and other self promotions has taken way too much of the attention. It shall not be a talk about me, but I have now played, rated and given feedback to 87 games and I have gotten 14 ratings. I have played games with a few ratings, but also games with a lot of ratings. Anyway it should never matter, it should be possible to get at least 20 ratings to nearly all games, and when that happens we can open for the self promotion.
Sadly has the issue grown a lot, and now it's become more and more a competition where we have to be begging for attention. This was much less of an issue just a could of years ago. I can as an example say that the first game jam I took part of, I got about 150 ratings without having to do any self promotion, now you have to fight to get just 10 ratings.
So like I have already said, use the promotion to make everybody better game jammers, and in the end it will not just give other people more ratings and feedback, but it will also help you. And then the game jams will be for YOU and ME.