I'd like to imagine that this is only the case here because of the jam's target audience. It's Brackeys jam and it attracts mostly young first time jammers that have completed their first game ever (since that is sort of the target audience of the YouTube channel). They are exited for people to play their game, but don't yet understand what the rating period is supposed to achieve.
They only see the strategy of rate4rate as a viable option to get peoples attention, but the only way to even notify the other jammer of your rating is to write them a comment. Usually something vague and nice (we don't want to piss 'em off after all and reduce the chance of them playing your game), to lull you into clicking on their link.
Honestly I can't be too mad at them, they are kids after all and kids are known to do stupid things. They will grow out of it by the next jam or two.
Personally I prefer the Ludumdare jam. Bigger numbers quash theses outliers and their karma system encourages you to write long and detailed reviews. I also like to look at the source code of novice and pro alike. One I like to help and from the other I like to learn.
Glad you have the right goals for the jam. In fact I'll have a look at your entry right now ;)