Exactly. But the thing is that the heart changes a lot, so you could hate someone for like 3 years, then slowly start to see them in a new light and suddenly BAM love! So if someone doesn't like you at first, and then slowly does, it becomes alright. But yes, choosing just for the sake of choice is just wrong.
But if she were to choose friend A and then start to like him after the fact, then it could be excused. Although he'd always feel upset that he was chosen just randomly... it would cause fear to be rooted in place and he'd always be nervous that you'd do the same again.