That's true in the sense that "everyone" knew that gay people should be able to get married. If you're under 40 and in tech, you're likely to be in a bubble of social liberalism.
"Respondents whose age fell between 30 and 65 were most likely to be in support of the measures, with the 18-29 age group being the most unsure. Those 65 and older showed the least support but were still a part of the majority approval"
http://www.statisticbrain.com/voting-statistics/ (census.gov is currently down)