Thanks for your reply, I agree that this is like the major reason why these posts exist. But quite a lot of people just are too afraid to say something negative, since they fear that they end up getting a worse review because of that. I've seen a lot of games where there were some design issues, that made the game much worse. I had that same experience last jam, where i had a really big problem in my game, which made it way worse. People trying to get a lot of ratings is something I don't think is too bad of a thing. It's always good to get more feedback.
And yes I agree, that the biggest issue is that not everyone plays the games that they've played, but that's not just because of bad culture. Yes there are quite a lot people that just don't care about returning the favor, but a lot of people are busy doing other things, so they just don't have time, since the 1 week period during development already takes a lot of time and you are probaly not able to merely focus on the jam and other people for 2 weeks. That's in my opinion unrealistic. R4R is of course not always useful, it's just one method of promoting your game. For example, I have recently started doing r4r again, I promote my game in the extra channel for that in the discord and I also mention my game a lot when having a conversation with other people in the jam channel. I also made a trailer and just in general try to play games. They all contribute to getting high ratings.
About troll submissions, I don't remember if these were here too, but there were people just uploading random friday night funkin mods, fnaf mods or similiar or other weird or suspicous stuff, but that was quite some while ago, but I don't remember if that was in the BGJ an issue.
And another thing is that quite a lot of people don't participate in playing other peoples games. These usually tend to be the lower rated people, due to the karma system. Getting ratings in jams is mostly about how much effort you put into it and how much you understand putting attention to your game. And rate 4 rate is just one of these methods, maybe not the best, but it's mostly working. And I don't want to say that low rated people don't put effort into their game, it also may be due to their thumbnail not being the right one or just playing the games of the wrong people. The bad culture was already a problem before, r4r may have exaggerated it, but it gives people a more reliable way to gain feedback.