Komaeda says this pretty frequently, and even latched onto Teruteru for his murder plan because he thought he saw the undefeatable hope that rises above every despair in him.
It's like... Hajime is out protagonist, so we can't see how Komaeda interacts with others, especially in a scenario where someone consistently attempts to get closer to him. So,
It might not be about "HinaKoma True Love OTP" and more like, Komaeda is a lonely person who's overjoyed and elated at someone, anyone to give him the time of day. He's not Hajimesexual as much as we can choose to have Hajime interact with him and thus, Komaeda develops an attachment for him.