I recently watched a video called "Draw with me", which is thought to be one of the most depressing works on youtube. It even had a "watch at your own risk" in it's tvtropes article. Now, perhaps this is just proof that I have a heart of stone (I really hope not) but I fail to see why it has that much effect on people. Sure, it is definately a downer, but its not going to cause me to break down sobbing.
So I looked this up after seeing your post and assuming this is the video about the boy and girl with the glass wall between them then, I concur, it didn't move me much. It was cute, sure, but I don't even see how it can be that much of a downer.
He could learn to draw with is left hand. His other hand will get better (unless it got cut off and I missed that somehow). Plus, there was some kind of great gift for him there at the end.