I think it’s telling that we as a society have become so desensitized to murder and crime. Between fictitious content of thrillers/crime and then non-fiction documentaries and true-crime shows/podcasts, I think it’s safe to say that nothing really shocks people anymore.
As to your point of asking if we sympathize with killers too much nowadays, I would agree. How many movies depict a sad backstory of a killer, how many true crime shows depict the tragic upbringing of the killer? We’ve been conditioned to feel bad for the plain, evil actions of demented people who yes probably had it bad growing up, but society should never be okay with that excuse for murder.