Kurt Cobain was never a man to commit himself or his band to any venture his heart was not in. Integrity was paramount to the Nirvana frontman. To a fault. While warming toward the end of his life, Cobain was never above scrutinising the sufficient punk cred of his fellow grunge peers, calling out Pearl Jam early as “careerist” bandwagon jumpers and, not wrongly, shining a light on Alice in Chains’ past as a former hairsprayed glam outfit before…