Well I know why
Because its still kidnapping, he still lived an awful life and he realized that after he went to normal. The queen’s affection/love for him doesn’t matter if you compare it to her actions. Remember mother Gothel from Tangled? She loved Rapuzel’s hair so she kidnapped her and tried to manipulate her. Remember yandere stories? They could kidnap their crush and though she loved him, her actions aren’t justifiable. Of course you would want to kill someone who put you through such torture in life and took you away from your loved ones. Pity? Who has time to think about that whiling taking revenge? Maybe a conscience but not pity
Comparing her to the queen in the book is unfair, she maybe scary and lonely she is completely different then that awful queen. Also she has Edmund or whatever his name is
Edit: i keep getting confused over conscience and conscious