Why do we celebrate columbus day when it has been proven that Leif Erikson was the first European in America?

Well,technically it wasn't North America,but Newfoundland is a damn sight closer to it than San Salvador!Besides,why should we celebrate the ACCIDENTAL "accomplishments" of an Italian explorer who brought to this continent racial bigotry and forced religious conversion when the only thing the Vikings(who knew WHERE they were going)ever brought to this region of the World was a deep seated desire to leave the cold?