3.9 rating of Sintez is not that bad but I'm hoping that it will go higher in the following days.
The activity seems good also as it is compose of different languages but they have very few followers on twitter with 699 only maybe they can increase it using bounty campaign.
How did the rating site get the information used for the rating? If this info is readily available they can share with the community.
They use information about whitepaper, dev, community, product to rate any ico. They have their own standard.