This is a fiction so take it in same way. You have to know that every child is a blank paper and the Kauravas were taught bad by Shakuni and Shakuni was influenced by Bhishmapitama because he was of the marriage between Dhitrashtra and Mata Gandhari. Kunti was not evil but you can say that her most important mistake was leaving Karna. So take it as the author's imagination. In the story the author want to change the things that led to bad personality of many characters in Mahabharat like Duryodhana, Ashwatthama. So let's read the full novel before declaring it good or bad.