Because its not the same argument.
I'd never make the argument that Goku and Vegeta are gay, because they aren't. I wouldn't for Yusuke and Kuwabara either. But Hiei and Kurama? Eh, could be, but theres not enough there I'd make a real argument about it.
Killua is in love with Gon. That could turn into something else when they get older, but its not a thing currently. They're kids, and I expect Gon to turn out straight, and Killua will never make a point of it. That's love, not just respect and camaraderie in there. The emotional breakdown Killua had over even falsley perceiving Gon choosing a girl over him says how deep that goes.
Guts respects and idolizes Griffith and wants to be his friend. And Griffith wants to use Guts as a tool. (And even specifically says Guts is NOT his friend, due to his lack of dream, which is what screws everything up.) It breaks him once Guts stops being so, and thats a super complicated thing, (More complicated than even Griffith himself knew) and Caska is sort of in the middle of it and ends up being a display of who is in control between them.
Gon and Killua are still kids. Guts is very clearly straight. Griffith is more asexual, but most of his advances, pretense or not, are towards Charlotte, (But there is no love there on his side, all an act) and after becoming Femto and having Guts at his Mercy, its Caska he decides to violate, in a display of "I'm better than you once again". Griffith and Guts is WAY more complicated than just "Griffith thinks Guts is hot and wants him in bed." And Guts most certainly does NOT.
Both complicated and very different relationships. In neither case do I think sex is a major factor. It might be an undertone to both, but… not a major factor in either.
Stage One: Denial, but yeah that's OK. We'll come back to this once you're ready to talk about it. Anyway, change of direction. Was there any point where Griffith's dream was noble? Part of me feels that had he been ignorant of the Beheliet (I know I fucked that up) he might have been satisfied just leading a band of mercenaries.