How about some research? Lefties are more likley to be alcoholics and schizophrenics--maybe that is why they aren't good closers.
Any article that cites the study saying that lefties are more likely to die earlier is simply manipulating statistics. Of the many studies of death rates of lefties vs righties, the study they are referencing was the only one which showed a statistically significant higher death rate in lefties. This study, however, was done second hand (no pun intended)- they asked families of dead people what hand the dead person used to write with. Second hand studies are notoriously fickle, and the methodology is no longer considered valid in many anthropological communities. Many, many studies (and I'd be glad to start citing them if you'd like) have shown that this study is crap.
So yeah, if you feel like citing invalid studies, we are more likely to die earlier. And become alcoholics. Oh, and by the way- there are 2500 left-handed deaths a year associated with lefties using right-handed products. And we're more likely to be good-looking, intelligent, and conquor the world (see Napoleon, Charlemagne, and Alexander the Great).