Peter Costello has done the right thing by himself and his family in pulling the plug on politics and deserves to have a highly successful career in the commercial world.

The move was clearly a shock to those who supposedly know Costello well – have a read of this ill-informed Glenn Milne prediction from Sunday morning.

Put yourself in Peter Costello’s shoes for a moment and you can understand his decision.

Within hours of the government falling, John Howard, Alexander Downer and Nick Minchin – three of the key figures who rebuffed him last year – were singing his praises as a great opposition leader. None were prepared to say they erred in resisting transition, or even publicly apologise to Costello.

Labor was clearly fearful of Costello because incoming President Mike Rann, Julia Gillard and federal secretary Tim Gartrell all claimed the result would have been worse if Costello was leader. That’s a big call and almost certainly wrong – especially considering Howard gave Labor its best result in 50 years and the way Gordon Brown turned around the polls in the UK after becoming Prime Minister. Besides, Costello’s vote in Higgins held up very well.

Life would have been hell for Costello as opposition leader. Malcolm Turnbull would probably have been a destabilising force as deputy leader and shadow treasurer and there would have been a destructive factional brawl in Victoria, with Jeff Kennett demonstrating yesterday what a callous and vengeful person he is.

For Costello to succeed as opposition leader, he would also have had to spend much of the next few months distancing himself from John Howard’s record, which would probably have triggered a destructive round of internal Liberal Party history wars. Labor would also have had a field day throwing various internal government documents at Costello.

Whilst he’ll probably be tempted to remain relatively private in his commercial pursuits, Costello should be welcomed into Australia’s most blue chip corporate boardrooms, diversifying the narrow gene pool of our directors’ club.

Nick Greiner is the only former politician who really made it onto the A list, but even he didn’t ever become chairman of a top 50 company.

Costello’s former Treasury Secretary Ted Evans has recently become chairman of Westpac and the man he appointed to run the Reserve Bank, Ian Macfarlane, has already outperformed Greiner in cracking three very big boards – Leighton, ANZ and Woolworths.

Costello would be a welcome addition to an international board like BHP-Billiton or News Corp. However, companies that will have to rely on Labor governments for their success will probably be reluctant to embrace him.

Despite his faults, Peter Costello was a far better Treasurer than John Howard was a Prime Minister and he deserves our thanks for his substantial public contribution and best wishes for the future.

You can only push a bloke so far and sometimes family should come first.

Stephen Mayne came fourth out of eight with 2.1% in Higgins on Saturday, proving Christian Kerr’s Friday correction wrong.