As far as genetics: I do have a gay uncle, though I've never spoken to him. My best friend's younger brother is gay as well. There is a genetic component, that is basically confirmed at this point. I, however, don't think that's the only factor (if even the deciding one). I believe, and pretty much always have, that people have a sort of "percentage of preference" that varies from person to person. I'm not a biologist, nor intelligent enough to write about something like that, so I generally don't advise much on that.
The article wasn't really on the genetic / choice factor, but on the practice of outing someone. I disagree with you on the notion that the entire community is against it. There's a very active debate on the topic, actually. The documentary Outrage! goes into it, and there are still movements within the LGBT community to maliciously out people. I don't believe this is compounded by the media as you suggest, mostly because I very rarely see it done in any serious news medium. The only place I've seen it advocated is in journalistically compromised websites like Gawker. It is, however, entirely present in the comment sections of news websites and message boards.
I also don't find any satisfaction at all in finding out someone who voted anti-LGBT ends up being LGBT themselves. There are dozens of reasons for this to happen, none of which are as important as someone voting as their electorate would have them vote. Do I think that's "right" ? Not really, but it's understandable. I wouldn't support a politician who was still against equality, obviously, but to break the entire community trust to disgrace them is disturbing.
I'm also aware that Jim Kolbe is from the later 90's, that's sort of my point. In the paper I'm currently writing, concerning the Electoral Politics of LGBT Candidates in the US, Kolbe's case is an important one. It sets a lot of expectations for LGBT candidates to deal with. This is still a real issue, as evidenced by the parts of the LGBT community that are going around and seeking out politicians to out. Rick Perry is a case where they are seeking to out a politician.