I don't know why or where you got all those conclusions from, but it seems maybe you didn't read it carefully enough. Chika knew quite well what he was doing. He knew Hotaka and used it to his advantage. Hotaka was half-assed because he had no interest in the relationship from the very beginning. It is shown in the entire duration of their relationship. Even Chika admits that he knows that Hotaka would say yes when pushed. But he also knew that Hotaka wouldn't say I love you because Chika had made all the effort to be a successor and Hotaka didn't have strong enough feelings to take him away from that.
Regarding Masato, it is shown from the very first chapter that Masato holds some strong feelings regarding Hotaka. He respected Hotaka's boundaries and didn't push as Chika did. He waited and respected him.
Yes, it's hurtful to go from one relationship to another, but Hotaka didn't quite saw the relationship as such, there was an expiration date in it and he wasn't really invested on it. What affected him was that he was STARTING to see the relationship as such but the feelings were still not there
I don't really remember much about the manga, because I've read it quite a while ago, but there were definietly my own feelings about my similar expirience involved. And I like a little pushy men, since the not pushy one for me turned out to be there just because it was conviniet and than once told me 'So I met a girl I'm seriously interested in, can we go back to being friends?'. Life. I generally also don't respect doing something half-assed for the same reason, because one of you can start having feelings on the end and it'll be hurtful. You should't give people hope or reasons just because you're weak-minded and can't set lines. That's cruel. So that's my point of view, maybe my emotions did a big work to my way of reading it.
I feel so bad for Chicka. This guy had some serious feelings and they were just tossed away like nothing. I was done something like this, maybe not that deep feelings, but anyway it'd hurt me so much that I can't imagine how the poor man coped with it. I really wished our life- and emotion-less uke had woken up and recovered for the damage he'd made. It annoys me how Masato was brought up. Using the gap after Chicka, when Hotaka was actually hurt. It's unhealthy to go straight from one relationship to another. Who I really hate is exactly the uke cuz he was just like 'I don't care' to everything. It's more hurtful than saying 'no' and he should've done it with Chicka if he was half-assed like we saw, especially after he was confessed to. Masato maybe wouldn't be that bad if he wasn't just replacement cuz come on, like for 5 or 6 chapters we had Hotaka with Chicka relation and then with no bigger (or rather visible) development comes a different guy for just two chapters. The characters were rather badly written or maybe just robotic main character?), I conclude after all. I don't even wanna mention the rock-like sex with no passion in it and again this uke who's like a doll with no needs or own will. Not good, I enjoyed it as long as I hoped there would be a real thing between Hotaka and Chicka. I basically don't like changing partners in the plot. Maybe if it's done right, like there is the tension between them and you can see something is going on, they desire one another or such. I didn't feel it. I cheered for Chicka with his slightly pushy behavior eventually. Low note from me.