Man,the Drama tag are there for a reason.Can't please everyone,i guess.
IMO,right from the beginning,Hoshino and Kobayakawa were both being forced into a situation that they do not want to be in but with time,they learn to accept each other weaknesses(Hoshino are bad at makeup to the level of nighmarish and Kobayakawa was a wimp with antisocial behaviour)but with every arc,they worked together with people around her and somehow,they were pretty much attracted to each other unknowingly due to them learning each other strengths(remember the chapter where his art teacher took Hoshino with her and Kobayakawa "unconsiously" searching for Hoshino?) before Kanou came in and confess to him,thus creating this pandemonium of him stuck between 3 people who love him.
Unlike any other romcom mc(except that one manga where a guy crossdress because he wants to get closer to girl he likes but somehow fall in love with her best friend because of her sincerity)he actually choose Hoshino out of 3 girls because of her daily interaction with Kobayakawa and whether you like it or not,she changed Kobayakawa's life from weak-willed and antisocial MC to a person who's vocal about things he believed in and are willing to confess his trouble to his friends as seen with his latest interaction with Nishikawa.Without Hoshino,he wouldn't have helped Matsukawa when she was being bashed by Kanou and he would't have known Kanou was his long lost friend from his elementary days.
Matsukawa have a weak case of good character development since she's there just as a "club member who happen to know their secrets",thus making her the weakest characterization by author to rationalize her liking Kobayakawa.Kanou have a good characterization as she's straightforward and will do anything to get what she wants,thus making her a prime candidate(by most of you lot actually) to be loved by Kobayakawa but he knows deep in his heart he's not going to be able to love such a beautiful girl since he sees himself as a hateful person and Hoshino is the first person who accept him for who he is and wanted him to change to a better person by trying to make him hang out with her friend though it ended in disaster.But hey,i might be wrong and somehow oversimplified this manga to suit my opinion.Feel free to rebuke mine,as long as you do it in a constructive,civilised manner.