Especially since it's entirely possible to find something funny in the context of a joke (that has no relation to any actual real people) and not think the subject is funny at all in real life when it happens to real people. Dead baby jokes, for example. A lot of people laugh at dead baby jokes because they're about hypothetical dead babies rather than real ones, so there's no harm in laughing at them. These people absolutely would not find making a joke about a real baby's death funny in any way because that is an actual, real baby who died.

It's the divide between fiction and reality, basically.