Yes, that's what I'm trying to get people to tease out right now. I don't think Carebear is cruel if he finds humor in that picture because he doesn't seem like that type of person. Someone, somewhere out there, I don't know. How does one tell the difference between the two, especially over the internet?
By trying to read between the lines, confront and ask and a dash of guesswork.

For instance you've figured out that I'm not the type of person, even if you stated above that people who find it funny are "sick and twisted".
Also I'm not saying I don't "get" what makes it funny. But someone thinking that's a laugh riot just because? No, don't get it. Which brings us back to motivations.
I'm guessing you "get" it then, but still not really get it. It might be your views and experiences are not set up right for the joke. Perhaps it'd be funnier if the joke was related to Saddam instead of US foreign policy. Or the misfortune of a sexual predator or a psychopath. Or something completely different you feel strongly about. Or maybe the type of joke just happens to fall down the wrong side of the balance for you, so you get too offended to find it funny, while some others find it too funny to be offended. It's never easy to tell exactly why humor works the way it works, but who we are, the experiences we have and things like type, nationality etc play an important part.
Perhaps. I think I like bitchy, mean girls humor more than morbid I'm going to kill my parents humor. Mainly because some people actually do it.
Aren't you aware that some people actually turn into bitchy, mean girls as well?
And a good deal of when to take morbid humor seriously and when to accept it as a simple humor depends on if the person making the joke is likely to act. When tragedy occurs, a coworker snaps or there's a school shooting we here people saying, "well the said they were going to do it, but I thought they were joking." This is a response I wanted to give in Sub's thread about his child's school but you really don't know when to take someone seriously and when not to.
Not sure I agree. I take the humor for humor and judge it based on the quality of the joke. When people say "we thought he were joking" it's normally when someone has threatened to do something concrete, not when posting morbid internet images or jokes. A threat about going on a rampage is a poor joke, and would make me fear the person posting it was serious, but that's no reason to stop telling funny morbid jokes.
I guess it could all be a matter of differences between Fi/Ti and Fe/Te. When the first pair is challenged, they don't call for any action. Not so with Fe/Te.