By Susie Beever The knifeman who slaughtered six people in Saturday’s horror attack in Sydney once hit out at a knife business online slamming them for “blunting” his blades. Joel Cauchihas been named as the 40-year-old who fatally stabbed six members of the public, before raising the knife to a police officer who shot him dead. Among his victims were 38-year-old mum Ashlee Good, whose baby was also seriously injured in the attack, 25-year-old Dawn Singleton, Jade Young, Pikria Darchia, 55, and security guard Faraz Tahir. A further eight people, including Ms Good’s nine-month-old baby, were in…