A large number of papers are subscription based. The full text can not be uploaded on ResearchGate due to publication policies. On the other hand, predatory journals are primarily open-access journals. According to ResearchGate, a full-text read has a weighting of 0.15 whereas an other read (like an abstract) has a weighting of 0.05! The score will be higher for a researcher who has more open-access articles than a researcher with subscription-based articles from journals with a high impact factor or Q value. Please share your opinion regarding this.
More information related to scoring is available here-https://help.researchgate.net/hc/en-us/articles/14293473316753-Research-Interest-Score