Just because it isn't talked about openly in the baseball community doesn't excuse his ignorance on the subject. He still lives in the same world the rest of us do, in 2015.
Religion doesn't make it OK to make statements like "I do disagree with the fact that Billy is a homosexual" any more than if he were to state that he disagreed with the fact that a person is black. We know homosexuality isn't a lifestyle a person is choosing to live, whether this is discussed in baseball circles or not is completely irrelevant.