You have to consider everything she went through, she tried reasoning with the girls, and I can see why she'd feel no attachment t to the other girls with all the timelines she had been through with them, caring about their well being AS well as Madoka's would of been an impossible task, she would of turned into a witch very quickly.
you could also argue that her wish forces her to act as she does
no i mean that her wish FORCES homura to do ANYTHING to protect madoka, not psychological
Makes sense, considering she made it to save Madoka. But Skelington still leans more towards just love of Madoka and uncaring of others. She seemed to like Madoka a lot more than the others even before she made the wish.