You are right , that there was no any insult against chinese mainland women in LGK's comment.
You say >>>Now, it seems to me the central issue in this squabble is that Lau Guan Kim said something about mainland Chinese women that Wchao37 found offensive.<<<
Obviously nobody here believes that this is any issue, leave alone "central".
I do not think that even these forumites ,who backed up Wchao in his rage against LGK had really seen any abuse against chinese women in his thread.
I bet that Wchao himself does not see this abuse. If I can understand the sense of LGK's words = everybody else can , so surely Wchao as well.(Yangsie is another story)
Why then does he repeat smiting LGK about this "abuse"?
It is as simple to answer as "why vlamingen and nederlanders do not like each other"?
It's all personal.