I don’t think it’s either/or, having empathy for someone who killed himself because of the horrible things his country persuaded him to do doesn’t preclude having empathy for his victims, and it doesn’t mean absolving the crime. It is reality that everyone involved is victimized by war.

the world already did what you are scared about to the Palestinians and is continuing to do so

Part of how this was done is by using the emotional weight of atrocities for dehumanization of those claimed to be responsible. You might say that we don’t need to acknowledge the humanity of everyone universally, because the murderers have crossed a clear line by their own free will. But there is a concerted effort to obfuscate that line and drag everyone into plausible complicity; mandatory military service, suppression and murder of journalists, manipulative propaganda campaigns, it’s all effective and hardly anyone is genuinely immune.

Which isn’t to say the framing in the OP article is right; saying slaughtering people like that is “difficult to accept”, “psychological trauma”, calling all the victims “terrorists”, makes what should be an issue of recognizing and reacting to injustice into a problem of medical treatment to get people to be ok with doing the evil things the state directs them to do. That’s more manipulative propaganda, and many people will be convinced by it. The simplest counter that is least subject to being twisted is the conviction that everyone is always human and should be treated with empathy, without exception.