I think your third point is what's most striking about the dissenting opinion. Not providing marriage licenses to couples based on the arbitrary criteria of sex is a deliberate act of denying a specific group of people access to marriage.

The women's and civil rights movements went against the traditions of plenty of millennial old cultures such as the "Kalahari Bushmen and the Han Chinese, the Carthaginians and the Aztecs"[0] as well.

[0]http://www.supremecourt.gov/opinions/14pdf/14-556_3204.pdf#p...