lazycoconut
I liked him when he wasn't a god
Ok, the Fujoshis part was a bit overblown, but from interviews, talks and some 4chan searching, it seems that not only Yutaka's fans but also a large part of the adult viewers liked Kaito for what he was and he got tons of free passes, even Urobuchi said at an interview that "at times you have to give in to the higher-ups but hold firm to the things you can never compromise on when writting a story", Kaito wasn't even considered to last more than a few episodes, at least in the original draft. From what I heard, the kids loved Gaim, which is pretty natural, Kouta is designed in a way to appeal to all ages and be likable all-around.
There seems to have been quite a lot of that in recent years, Date, Hayami, and Bishop were all kept on their respective shows much longer than they were intended to be there, just because of their popularity with fans. Date's understandable I guess because both he and his actor were very charismatic but the others, plus Kaito ... I guess people love a "bad boy", no matter how awful he may be?
That's surprising though, Kaito was only going to be there a few episodes? Do you have a source for that? The first episode's opening, plus the imagery in the OP, would have made me think that he was always going to be Kouta's final enemy/rival