First of all, he is not sympathetic at all nor is sympathy a requirement for a 'viable character.' Vince Gilligan, the shows creator, certainly believes we are long past the sympathy point for Walt. But of course he only helps write the show, what would he know? it's all interpretation now!
Anyway the mere thought that a character needs to be 'sympathetic' to be viable is disgusting and a stifling limitation on creativity: some of the best written characters in history are completely unsympathetic. If you require that, you most certainly require it on your own terms. Don't bother applying such absurd standards on the rest of us who. I certainly don't need to be coddled to enjoy television.
Finally, none of my comments at all suggest he should turn himself in. I think the show must end with him dying or getting caught, but that's at the end of the show. My comments merely suggest that it's time people accept Walt for the completely unsympathetic monster he is. And I love every second of it, it is the very thing that makes the show compelling.
Now, why don't YOU go grab a soda or pet your dog: you're clearly the only one upset here. I am loving every second of the 'Walt is sympathetic' crowd going up in flames. It's a magical moment and so, so much fun