Nurturing a child can be a challenge, but it was part of our human cycle to have an offspring to continue our legacy, and to have someone to bear our name and be part of our lineage.
Generally, parents will want to have a well-behaved, and successful kid when they grow up, who somehow aligns with the social norm as well as the values that the family has.
But humans are unique altogether, although they might share identical DNA, but in the end, they will grow into very different individuals with their own uniqueness and their own personalities. Even identical twins or the conjoined twin will have their own way of thinking.
And that is the reason why sibling has very different output un the end, although they have been raised with the same value and love of the parents, growing up in the same neighborhood and the same influence.
so whenever you see a sibling that behave differently, or in the opposite direction, don't judge the parents for the love that they give, but understand that every individuals are different on their own.