Not really... I'd only be emotional in those situations if I knew the victim, or I was the victim myself. I think if he doesn't value life he doesn't deserve it. It's that simple for me really. There is no point keeping him or Martin Bryant or anyone like that in a cell forever. It's ridiculous to waste the resources on him tbh.
And your argument about wiping out Africa is totally different. How can you justify killing Osama just because he would be hard to capture. So to you, it isn't their crime that warrants death it's how hard it would be to capture them?