I'm going to try once more at rationality with an analogy that I think works on all the levels...
"I think it's worth it to have a cost of, unfortunately, some gun deaths every single year so that we can have the second amendment to protect our other God-given rights. That is a prudent deal. It is rational." -Charlie Kirk
I fail to see how context changes this. No amount of self righteous scolding will elicit tears for this racist homophobic piece of human garbage and it takes half a second of looking up his views to know he would have laughed and praised the deaths of multiple friends of mine if it scored him brownie points with his audience. Won't get a tear from me. And nobody should feel bad laughing at the irony of a man who thought others' kids' deaths were acceptable, dying in a way he said was acceptable for them.
Okay, look at Charlie Kirk's quote above. He's for the 2nd Amendment. He's acknowledging that the freedom to have guns is going to come with the consequence that some innocent people will die from them. He is saying that is "acceptable loss" essentially. Now, I don't entirely agree with this, I think there are compromises that could be made to keep people safer while also allowing freedom to own guns... but that's a different topic. People use a quote like this to justify laughing and cheering that this man was brutally murdered in front of his family as schadenfreude or irony or "just desserts" or whatever... but I'm going to try a rational approach.
In the American justice system, if you rape or kill, for instance, you have a right to a trial and a jury of your peers. You also have a right to a lawyer for defense. Our criminal justice system is not perfect, but one of the tenets it is built upon is the concept that it is better to let some guilty men walk free than to punish even one innocent person. Of course, historically we have failed at both... but the point is meant to be that everyone gets a fair trial even if you think you have the guilty person in custody because you want to make 100% if you can that you punish the guilty person and not an innocent one.
So... imagine a person who vehemently supports this. Someone who does not like mob justice or knee-jerk rulings or shoddy police work that leads to an innocent person being in prison for decades or being executed for a crime they didn't commit. Many such people exist. Sometimes, though, this does mean a rapist or a murderer will get away because the case against them cannot be proven without a reasonable doubt. The family of the victim of that person's crimes will be angry, and justifiably so that they see the perpetrator get away with their crimes.
Now, imagine the lawyer who advocates that everyone gets a fair defense, and he defends someone and successfully gets a not guilty verdict... but the victims' family is sure the guilty man got away with murder... Now imagine that lawyer gets killed by someone who, when they catch him, they discover is someone with a record of previously having been accused of a murder and found innocent and literally got away with murder... only to kill a lawyer who defends such people and advocates that it is better to let some guilty go free than to punish innocent people.
Would you cheer for that lawyer's death? Would you laugh at the irony? Do you think the lawyer who defends and gets murderers free deserved to get killed himself by a murderer who was free thanks to such beliefs?
That's the core of what we are talking about here. Charlie Kirk might have been a horrible person. I honestly don't know because I heard enough from him that I tuned him out because I didn't like him. But the glee supposedly nice and good and fair people are showing over his death because they strongly (and perhaps fairly) disliked him... it makes no sense if you're someone who believes in rights, believes in good, etc.