Depending on your definitions (empathy, sympathy, and compassion are often confusingly defined and contradictory between dictionaries), you ARE empathizing by realizing they are mental children. You’re just not sympathizing and therefore deciding no longer to act with compassion, which makes plenty of sense to me.
IMHO it’s good to empathize with the right (understand your attacker), but it’s also important have to understand that whatever the underlying reasons, these people, when activated into an idiot army they become a dangerous group.
The definitions that make the most sense to me is
Empathy - understanding the perspective of another, where there desires and fears come from. It takes intelligence to not just project one’s own personality on everyone else and understand that they are different.
Sympathy - Feeling in sync with another (like when you speak of sympathetic guitar strings causing each other to vibrate). Like you see the bombing in Gaza and not just understand that they don’t want to be bombed (empathy), but imagining the pain of losing your child.
Compassion - The positive treatment of another due to having sympathy for them