I'd argue that the fact that there is a trend to whataboutise in China threads has more value than the actual whataboutism. It may not be a lot but it doesn't need much to be more then a whataboutism.
To urge people not to engage into this pointless debate, you won't change their opinion by calling it whataboutism and will only enforce it since neither you nor him provided any valuable points in the discussion.
Where is the value in your comment?