Just a few brain farts from myself
He was not terribly likeable/relatable with his union ties and somewhat dynastic background.
He was a capable administrator but not a very good politician.
He was up against the full might of Howard's media alliance. Media coverage of Crean was lukewarm on his accomplishments and trumpeting at his fumbles. Coverage was so one sided it hurt.
In my opinion a Crean government would never have happened because he was a clever man in a stupid world. Labor were trying to sell nation building when all the voting population was interested in was war-fervour and lining their pockets. Only when Labor switched gears with Rudd and started playing the populist game did they manage to achieve some political success. Truly dark times in Australian politics.