a) are possibly homophobic, or a closeted homosexual

and

b) enjoy certain privileges as a white, heterosexual, (cis) male

Is not meant to be a personal attack, IMO, but a wake-up call. Read it again, as if danparsonson were talking to a third person, and maybe you'll gain some new perspective.

If you feel like marriage has had an immutable definition since forever and just now, people are trying to change it for the first time, you should check your facts: http://en.wikipedia.org/wiki/Marriage#History_of_marriage_by...

And words do matter. You can tell a lot about a person or culture based on the words they use.