I don't think it would kill your will, maybe give you reason to work harder even. Also, there are a lot of variables... what caliber player you are, the way you lost, who you played, the list could go on. I think it would be more damaging to the very elite. I can't even think of an example of that happening though.
Ask Mika. Corey Duel beat him in the finals 11-0. In the finals!
That would suck majorly Mika is defiantly in the elite group