I'm a tour director. People ask me sometimes if a place is vegetarian-friendly. I'm not a vegetarian. I don't normally pay attention to the things that would matter to a vegetarian. So I don't pick up on that just by visiting there. To answer the question, I'd need to go there and purposely give it some attention.
Gay-friendly is like that. If you haven't picked up on it one way or the other, you're the wrong person to answer the question. There's no shame in that. Don't try to pull an answer out of your you-know-what. Just tell them you don't know, and they should ask someone else who does.
Bob, if you think gay people don't draw unwanted attention just by our presence, you haven't been paying attention. For a lot of couples, straight or gay, enjoying a beach or sunset means you spend some of your time holding hands, sharing a quick kiss, or otherwise displaying your sexuality in visible ways. When a gay couple asks if a place is gay-friendly, they want to know if they can safely hold hands without being harassed for it - just enjoy a worry-free, hassle-free vacation like every other couple.
It's a common concern for LGBT people visiting an unfamiliar place. My tour business isn't just for LGBT people - for everyone. But as a gay man, I do pay attention to how gay-friendly a place is. And many LGBT people like to know the place they'll be vacationing, and spending their limited time/money, is a place they'll feel welcome.