So you believe this will work because people will feel bad about lying to themselves and others online? To quote Tycho Brahe on a similar plan, 'you presume a degree of humanity in these people that, frankly, doesn't exist'. Cognitive dissonance is a part of every day life, one more will not make a person question their ways.
Props for the effort at least. Not very many companies would even attempt such a thing, and they admitted up front they know this won't mean a thing to the real hardcases, but maybe to the people (like me) who have a habit of becoming angry and blaming others for a loss when normally they're far more rational. Yes I play DotA 2 and yes, I am awful. Takes years to learn after all.