This is common with "evil" characters. Abuse is a cycle etc. I assume the idea is to show that humans aren't born monsters or wholly bad. If done well it stirs up an amount of empathy and understanding...but it almost always ends up disregarding ones accountability for their evil actions. The victim now must be the bigger person and embody a spirit of forgiveness with no retaliation. Its lowkey emotional manipulation. It can be annoying and so unsatisfying at times though when some heinous behaviour is explained away like this. I agree with you but it depends on the context mostly.
