Even if he was mentally sick for his entire life, he still made choices. Mental illness doesn't force you to abuse drugs. I can be a contributing factor sure, but in the end those choices were made by him and him alone. Unfortunate that mental illness exists, but I'm not going to mourn over a man who chose to take his life in that direction. My bestfriend contemplated suicide years ago because of his depression. He said that he didn;t go through with it because he realized that he can make his own life what he wants it to be and that you can fight depression. He didn't blame anyone or anything for choices he had made. Man makes his own choices regardless of outside interference.
Then your best friend obviously wasn't suffering from as severe of a case of mental illness as this man was Armbar. I'm not saying depression or mental illness is impossible to overcome, just that those who haven't seen it and struggled with it really do not understand what leads a person to these thoughts and actions.
Why shouldn't we have sympathy for a talented young man who unfortunately passed away today, most likely from taking his own life? That's a damn shame, of course he should be mourned like anyone else should be.