Why do planes carry 'crash axe' with which Indian pilot Smit was attacked?

It's mandatory for every commercial airline to carry a 'crash axe' to deal with emergency situations. Earlier, axes used to be stored in main cabins, but were shifted to cockpits after 9/11 terrorist attacks. Now, weapon is stored within easy reach of pilots in cockpits. Notably, Indian pilot Smit Machchhar was stabbed by his Omani co-pilot with a 'crash axe'.