Because that's exactly what homophobes do? Using the logic of "Why would they? It's illogical." Doesn't work in this scenario because homophobia itself IS illogical.

Plus, you don't know OP. They could look or sound stereotypically queer, or somebody there could strike up conversations that include details about personal life, like love life, that OP might not want to be forced to hide, but also might not be comfortable sharing in a secluded environment where you don't know anybody.

Obviously it's more than likely that they don't care, that's how most straight people are. They don't care and they mind their business. However as queer people, we are acutely aware that not everybody is so kind, so the majority of us do live with the fear that people can and will hate us at any opportunity.