Ronan's father just wants him to grow up so he can become a good man, and in turn, he can become a good Alpha, but when Ronan thinks Alpha, he thinks power, which he can misuse for his own pleasure. He doesn't understand that being Alpha is the opposite; you have to sacrifice your own happiness for everyone else. You have seen him. If he becomes Alpha now, then his pack will go haywire.
Ronan has a younger sister, so if he doesn't get his act together, his father may disinherit him and give her Ronan's birthright as the firstborn to become Alpha.
His mate enters the picture because Ronan is a chronic womanizer, which is his biggest flaw. He's young, but he can't resist females, which will result in him being killed that way or doing something stupid for a female that will put his pack in danger. Therefore, logically, his father believes that if he marries, especially if the girl is his mate and if he loves her, he'll leave at once.
