Yes the first of anything is tough and controversial! The key to this whole topic is that the media wants this to happen not the sports world. Everybody and their dog are hush hush on this topic from the teams, but ESPN is pulling up statements from a free agent. The teams know that this would be a bad thing, or else why not talk about it?
The BIG idea out there is the moment that a team says yes to a gay, they are forcing the fans to pick between the Bible and supporting that players actions. If the concern is true the owners know It will be a ghost city in the stands. That idea may seem like a small issue to you but I believe the owners have done the research and put the muzzle on!
I don't think it's at all true that the 'sports world' doesn't want this to happen. There's plenty of outspoken athletes and owners who have strong feelings on this. I don't think teams 'know' this would be a bad thing - that statement alone implies that, objectively, this is a 'bad' thing. I don't see how confronting bigotry is a 'bad' thing. It's a scary thing, sure, but those two words are not synonymous.
Someone else has already pointed out how bizarre the 'Bible or team' argument is, and if you honestly think a team will fail economically because a single player on it is gay, I think you're wildly over-estimating the percentage of people who are fervent enough in their anti-gay beliefs, particularly enough to REFUSE to support a team with a single player on it who does something they disagree with.
I also am not sure what 'research' you're talking about. I'm honestly not sure you know what you're talking about. There's no 'research' that the owners could have done. They haven't 'polled the audience.' People are afraid, and that makes sense.
I get the impression that you have very strong reservations about an openly gay athlete, and I respect that you're trying to present them in a well-reasoned way, but I honestly cannot comprehend the words you are saying. They don't make sense to me. They are laced with an assumption that, fundamentally, having an openly gay active athlete is bad or disruptive. I understand that you separate this from your belief of what a person should be allowed to do on their own time, and I respect that distinction. I think you're trying to communicate that you have misgivings about this issue but that you think gay people should be allowed to do whatever they want behind closed doors, which is different than being 'anti-gay,' and I respect that. But I'm not sure I really understand the logic in your argument.