Your father was the reason Krueger's sister died, and therefore Krueger resented you as well for having the same surname as the guy who had ruined his entire life. He wanted to get revenge for what your father has done, so he made the decision of becoming your bodyguard. Hired by the very man who had ruined his life. But of course, your father doesn't know that he hired the person whose life he ruined to get close to his daughter and to get revenge by taking something he loved dearly as well.