They are not credible, and are basically what I call wordsmith weasels. I advise you to stop wasting time with these trolls, honestly. If someone like me from India can get it right, anyone should be able to. The key lies in moral integrity. They lack that.

The downvote patterns are observable in this thread, as are their argumentations like quoting not the institution (CPC) but a Western encyclopedia like Britannica as an authority on CPC. This reeks of their Western chauvinist attitude towards rest of the world, which I want to see dying off of this planet.