I disagree. The act/event is bad/evil because, on the one hand, the "perpetrator" is doing an evil, and on the other, the "victim" is suffering an evil, thus making the act evil. Evil is not only something that is suffered, but also something that is committed. It not only has to do with us feeling empathy and putting ourselves in the place of the "victim", we can also put ourselves in the place of the "perpetrator" and see what he did as a mistake that we would not want to make.

Also, objectively it does not refer only to that which exists as matter, it also refers to that which exists independently of the observer (subject). I could then say that objective truth does not exist either, because it does not exist materially, which is a self-contradictory argument because by saying that objective truth does not exist I am affirming that it is an objective truth that objective truth does not exist.