Some women aren't hypergamous, but that doesn't disprove the observable fact that most are.
This is how scientific observation works.
This is like black and white, chalk and cheese, young and old, yesterday and today. You will actually find that in todays day and age women actually prefer someone on the same intellectual basis. Scientific studies carried out and quoted was more so quite some many, many years ago when women did not have a voice in the business world. Off course she wanted to ensure her children had food on their table but even then, a lot of women coupled for love.
Again, yes there are women who deliberately seek financial security, wealth. There are men that deliberately seek a "handbag".
And then there are women who deliberately seek a "type" just as much as there are men the deliberately seek a "type".
You really can't put women in this 90% are and 10% aren't category.