Come on now, it's not just about being afraid of rejection. Coming out can be dangerous and in the worst cases, even life threatening. Those guys are twice Jiwon's size. He was word vomiting while trying to diffuse a potentially unsafe situation. (Yeah, his friends didn't seem like the type to become violent, but unfortunately, it's still far too common in our world for violence to happen to people in the LGBT community.) Let's not forget, Jiwon has a history with (and trauma because of) physical assault as well.
I don't actually think he was legitimately saying he's okay with homophobia.
That said, I do wish the author has chosen the words he said there differently/with a little more social awareness.
Of course, I took a shortcut by simply saying "afraid of rejection" because I'm well aware it's much more complex than that. I'm obviously aware of the violence and even sometimes the oppression that people in the LGBT+ community experience (I'm part of it myself), and that in some countries it's even illegal.
In the character's situation, they can't just blurt it out without really thinking about the potential reactions. There needs to be time for analysis to understand how these people, and yourself, would react, because if you're not prepared to hear an unpleasant response, you simply shouldn't say it. So, taking a step by announcing it is all well and good, but you have to know when to stand by your position.
And I agree, the author didn't choose the right words, it leaves me very perplexed.
What do you mean, "I understand if you don't support gay relationships"? Bro, that is clearly not ok to not support, In my pov if you don't support them, it means you're homophobic. So, even if you're afraid of rejection, I still find it very strange to say that. If you have the courage to say it, you also need the courage to stand up for it; being gay and owning it remains a deeply political act. It’s infuriating to see this character back down so much.