I would not say he was a bad father. He was actually fairly decent. He was a provider, he built a stable home with Laura. He loves his children. He showed affection. He communicated. He was supportive when he had to be and gave tough love when needed. Bottom line, he didn't avoid his children like Lucky has done to Aiden. Even when Laura's rape was revealed. Luke tried to explain it and after Lucky shunned them both--he still made attempts to repair the damage to their relationship.
Luke is probably turning over in his grave over how his "cowboy" has behaved.
ETA: Yes. Luke had mob ties, which brought violence into their lives, but to please Laura, he did get out of the business for awhile. And he took his family on the run to keep them safe and escape the mob life.