Okay. So this is my first non-introduction post on the forums, but I stumbled across this post which had a lot of generalizations with very little information to back them up, and I thought I would contribute a few things. I actually recently did a lot of research on gender disparities amongst hobbies generally considered "intellectual" by the public, mostly Chess and Rubik's Cubing. (Not to say that I think there is correlation between cubing and chess abilities and intelligence because research does not suggest this in the slightest.)
I personally do not think Official World Records should be split, but I do think having quick access on the WCA website to the top 100 female cubers would be extremely beneficial to female cubers. A debate like this has also been had amongst the Chess community, not surprisingly, and I apologize that a lot of my references are about Chess, there isn't much data on Rubik's Cubing in sociological or psychological fields, but the two sports do have quite a bit in common in terms of how they are typed as intellectual and their need for spatial intelligence and reasoning skills. I can't say why the speed stacking is split amongst genders, but Chess is split amongst genders to encourage female participation. The lack of female participation in "intellectual" sports is in part due to old ideas about female intelligence and how women and men are encouraged differently to pursue their interests. This lack of participation creates a smaller sample size of female cubers which in turn leads to fewer outliers (the kind of people who might hold world records) and thus women don't get world records.
The IQ point was pretty moot considering that women and men have pretty comparable IQs and also that the IQ test has been shown to largely mean nothing in terms of intelligence and intelligence isn't required to solve Rubik's cubes anyway. The only difference amongst genders I can think of might be spatial reasoning skills which men have been shown to generally perform better in. However, there was a great study done about preschoolers solving puzzles that showed girls were more likely to be shown where to place pieces and boys were more encouraged to "figure out" where to place the pieces thereby fostering development of spatial reasoning skills in boys more than girls. So maybe if someone's parents and teachers were consciously or subconsciously underestimating their intelligence because they were female they might not have developed equal spatial intelligence. (That was sort of off topic, but this stuff is really interesting to me so I blabbed a little bit.)
There's also data to show that when women compete with men they perform substantially worse than when they compete with other women or the same men they are lead to believe are women, so I think that alone is reason enough to have UWRs for women because it will encourage better performance. (The article is by Christian Jarrett if you want to look it up, my school's databases won't give me access to the full text any longer.)
It didn't seem like anything came from the thread, the WCA still doesn't list top 100 female cubers and I sort of wanted to bump this to see if those steps could be taken and also because there might be people who are interested in some of the data I shared! (If you care about this stuff I could PM you some good reads.)