I wrote to them asking to improve the same by considering PostgreSQL user group discussion too for their ranking algorithm. Below is the response I got:
Hi Sameer, Thank you for your interest in our ranking and for your proposal. We are always looking for ways to improve the ranking method, and any ideas are very welcome. From the figures we have we don't see a significant advantage or disadvantage for open source systems caused by their specific communication channels, but we will closer investigate your suggestion at our next ranking evaluation. all the best Matthias Gelbmann
I am going to provide them with a link where they can track user discussions and its frequency. Is there any consolidated view/search/count for all the different user forums we have in PostgreSQL community?