It is probably correct. For one, only about 1 to 3% of the population identifies as "gay." For another, being "gay" is about a lifestyle more than a sexual orientation. And that lifestyle does not include monogamy, which seems to be very rare among homosexuals, especially male homosexuals.
You’d be surprise how much monogamy means when there’s a joint tax return option awaiting, instead of the higher amount “single” designation.