Joseph and Benjamin were the sons of Jacob's first love, Rachel. His favortism toward Joseph was simply bad parenting. [Joseph's] mother being dead, his affections clung the more closely to the father, and Jacob's heart was bound up in this child of his old age. He "loved Joseph more than all his children." But even this affection was to become a cause of trouble and sorrow. Jacob unwisely manifested his preference for Joseph, and this excited the jealousy of his other sons.
i agree, this is just one part of the story but in context to Jacob life there was a lot of struggle, and GOD allowed it.
From the beginning GOD disliked Esau but not Isaac who loved him more than Jacob.
GOD's birthright and promise is with Jacob and not Esau, but to our carnal sight we discern it wrongly since being wise in our own sight.
In our sight we discern that Jacob stole the birthright of Esau, but on the other hand, Esau gave it willingly because his craving for Jacob's delicious broth.
And Esau realized it later he was tricked, and Jacob had to fllee to his uncle Laban, and there the craftiness of Laban cheated Jacob all for his own gain.
On the other hand, both sisters were competing even using concubines, who can give Jacob more children so he would love one of them more than the other.
When Jacob and his family came out of Laban, Rachel stole her father's worshiped idols without Jacob's knowledge and hid it all along, even covered and sat on it while Laban was going through all their belongings.
Jacob in order to convience Laban who couldn't find it and knowing his family didn't take it, he cursed the one who took it, and for Laban to leave them alone. (and the curse took Rachael's life)
After all that, Jacob was able to make peace with his brother Esau, and lived with his family peacefully and never blamed, dispiced nor shun anyone from his family.
He brought up all the sons well, just that besides young Joseph and very young Benjamin at home, the other grown up sons had mischievous and dodgy character.
Whether at home behind the father or in his absence or in the field, apparently reported by young Joseph, and which grieved the father.
Often Joseph was sent to check on them and as usuual he reported accordingly, which also created the resentment of the grown up brothers.
i believe it was natural that the father pampered the still young and innocent children than the grown ups who suppose to man up and work for the family in discipline and maturity.
Since soon also they'll be handed out in marriage according to tradition, and the other things of Joseph from GOD only fueld up the ungodly immaturity and undisciplined nature of the brothers.
Bad parenting?
Not much so, it's about traditions of those days and about GOD and parents fearing children, doing the right thing by age, end of the day pleases the LORD GOD of Israel/Jacob.
To GOD, Jacob was among the significant figure compared to all of the sons, where some became 'redeeming instruments' of HIS to keep the linage alive and going as the 12 tribes of Israel/Jacob.
Because when GOD appeared to Moses, HE revealed HIMSELF as the GOD of his fathers, the GOD of Abraham, the GOD of Isaac, and the GOD of Jacob, ................. (Exodus3:15/Matthew22:32)
Shalom in the name of Lord Jesus Christ.