There's a limit to the human attention span lol. You can only express outrage and sympathy for so long. They will move to the next new thing and forget Syria just as easily as they got caught up in it (but for a few, bc that's our nature) , esp since Syria's new norm will be the state it's currently in for quite a while now.
I don't get why you're acting like sympathy is only for one's own, or why it's a thing of outrage for u to see it expressed towards others. As if sympathy is a tangible thing that builds roads or feeds the starving. If it were, then I might understand u.