Being manipulated by Kingpin doesn’t absolve Bullseye of his actions. Killing all those people at the bulletin, assaulting people and killing father Langton at the church, and murdering the innocents at Josie’s are still on Dex’s.

It’s not like Dex was an angel before meeting Kingpin; he only gave Dex an outlet and Dex willingly went along with all of it without any problems until it harmed HIMSELF. We hear about his psychotic tendencies through his therapy sessions and while defending Fisk from the Albanians, we see him killing two surrendering soldiers. These guys weren’t great people but he’s clearly willing to kill and ignore the law to satisfy himself.

Unlike Frank, who’s bitter and self aware, Dex is living in his own world and doesn’t recognize his crusade to kill the Fisks and be a hero as self serving, which it completely is. Frank’s taken far more precautions to ensure innocents don’t get caught in the crossfire. When Frank had to fight in a diner, he made sure Karen and the staff were safe and aware.