I obviously don't get it

The Daily Caller has an amusing story about a Pennsylvania state house Democratic party primary race in which Gregg Kravitz claims to be bisexual while his opponent, Babette Josephs, counters that Kravitz is a "closeted straight man" trying to curry favor with gay voters.

The part I don't get is a quote from Kravitz:

I want to be completely open with how I am proud of my bisexuality.

Why does one feel the need to express pride in their sexual preference? Isn't that a bit like expressing pride in your preference to, say, brunettes over redheads?