He was a huge success as a person. On and off the field.
He was let down by the industry. They roomed a young kid, along way from home, with a drug trafficker and left him mentored by a drunk and coached by a bloke who's management background involved 1 year at a WAFL club. Then treated him as a pariah because of it.
Then he got buggered about at Fremantle by a coach who was so lazy that he left selection to the fitness meatheads, who kept running him into the ground.
Even at Melbourne, who get credit for giving him a chance rather than Bennell getting credit for never giving up or dropping his head, they let them all get on the grog when they should have been preparing for a potential final, presumably because the old blokes who'd gone up there to escape quarantine were getting twitchy, and - what a shock - a bad decision is made by someone who hasn't had a drink for a long time.
And before the personal responsibility crowd jump in - he took it on himself to retire because of it.