The 74-year-old says he is leaving to spend more time with his family, including his six grandchildrenFinancial journalist Alan Kohler, a familiar face on the ABC’s 7pm news bulletin, will retire in December after three decades as the public broadcaster’s highly-respected financial guru.Now 74, Kohler has been presenting finance, complete with idiosyncratic graphs, on the ABC for almost a quarter of a century, signing off each evening since 2002 with the catchphrase: “And that’s finance?