It seems like the central question is: why do they lack a partner? Some possible explanations could be:
1- They are too picky
2- They are undesirable to potential partners
3- They are unwilling or unable to mingle with potential partners
The author of the article seems to blame men for not being interested in these high-performing women (i.e. reason #2 above), while Inhorn seems to suggest some balance between #1 and #2.
While I don't belong to the cohort under discussion, I used to be very focused on my career and would not have been able to find a partner had I not met my wife in college.
In other words, I don't think reason #3 should be dismissed without further data, although personally I suspect reason #1 is also much more common than #2.