It's understandable that itch.io have the filters they do given the core use of the site is not game jams, but rather serving as more of a library.
And there is no silver bullet, but the current default random filter we have currently is uneven and unfair.
Visibility should be a function of participation, favouring those who are rating others and engaging in critical feedback and praise.
I agree that Ludum Dare's Karma system would be a good model to start from as it's been proven to work well for the last few years.
The current reliance on spamming the community with "Play my game" and "I'll rate you if you rate me" in order to achieve an above mean average rating count is frustrating and discouraging.
GMTK brings a level of popularity and attention, but with increasing numbers the amount of spam is growing and could turn the community toxic easily.
Whatever changes are made to address these issues however, should be done in a transparent and iterative process with the community, with regards to the various game jam formats itch.io hosts.
I'm excited to see itch.io create an even more welcoming and supportive breeding ground for aspiring developers.
/endrant