Asked whether clubs such as Muirfield (next year's hosts) should be awarded the event in future, he said: "In all honesty, no."
Yes, this playing member of the Marylebone Cricket Club – so recently itself an enclave of anti-female prejudice – told the golfing fraternity their attitude simply isn't, well, cricket.
Even Saudi Arabia and Qatar sent women to the Olympics this year, but the male fundamentalists at the governing body of golf, the Royal and Ancient, remain resolute in their female fatwah. They do not permit women members. Nor does Royal Troon. Even Augusta National, a notorious former bastion of racial and gender discrimination, has fallen.
Robertson has joined a succession of politicians to have condemned the R&A's arcane sexism: First Minister Alex Salmond, Scottish sports minister Shona Robison and former Prime Minister Gordon Brown.
Private club members actually have a legal entitlement to pose as dinosaurs. Yet, in an interview with a Sunday newspaper, Robertson said he regarded it as "increasingly anachronistic not to allow women to be members".
He conceded an entitlement to determine their own right of association, but said there is a different slant when "a private club fulfils a public function, such as staging a major event".
Robertson's view echoed that expressed days earlier by the out-going chair of the British Olympic Association, the Tory peer Colin Moynihan, who urged the R&A to join Augusta and drop its men-only membership. Prior to last year's Open at Royal St George's (another men-only club), Peter Dawson, the R&A ceo, said they didn't "use the Open for social engineering . . . We have never been particularly concerned about a club's policy".
Outposts of exclusion have been falling, nudged by the Equality Act (which is not exclusively helpful) and the fact that non-compliance threatens lottery funding.
Not even Her Majesty, patron of the MCC, would have been admitted to the Long Room prior to the cricket chaps changing their rules in 1998. After prolonged flannelling, the motion barely squeezed the required two-thirds Lord's majority.
"No sponsor wants to be involved with an organisation whose image is elitist, fuddy-duddy and old fartish," said the MCC's then head of public relations. The chairman who brokered the change was recruited by other bastions of misogynism. Boodles was said to be among them but, like the Garrick, it remains all-male. So does the secretive Bullingdon club at Oxford, of which David Cameron was once a member, and White's in London (founded in 1693) which the Prime Minister subsequently joined. Cameron's father was formerly White's chairman.
Demonstrations of elite male privilege are legendary, like the Bullingdon's rite of passage of trashing hostelries or cars. They seem little different at Cambridge. When Magdalene College admitted women in 1988, male students wore black armbands and carried a coffin through the quad.
Just toffs' japes among kindred chums, though. Harmless, surely? Well no. It's a tradition on which the ruling classes have been weaned: promotion of a resolutely male environment from which potentially civilising female influence is excluded. It's not just Neanderthal. It's immoral: as indefensible as exclusion of Jews, Catholics, blacks, or homosexuals. The R&A will surely eventually recognise this for what it is, and squirm. The vast majority of clubs in the sport they govern admit women. Yes, there are women-only clubs. It's little wonder why. Yet only a handful of all clubs mirror the parent body. The rest must wonder at the contradictions of their stewardship, bamboozled by a stance so at odds with their laudable efforts to broaden the appeal of the game.
The R&A will have been given food for thought by one of the establishment's own going on the attack. Robertson is not quite Eton and The Guards, but very close to stereotypical Tory tradition. Challenges from left of centre are common, but this is an assault on a new front.
Robertson was educated at The King's School, Canterbury, among the world's most ancient schools. He did an honours degree at Reading and reached the rank of major, leading the Household Cavalry at the State Opening of Parliament, but also seeing active service in Ireland, the Gulf and Bosnia, before working for an investment bank.
The R&A told Herald Sport they would be making no comment meantime on his views but, as Muirfield prepares to host the Open, pressure will intensify.
Golf has as yet made no business case for UK Sport funding for the 2016 Olympics when it returns to the programme. A new body, invoving the four home golf unions and the PGA, is being formed. It will nominate the GB team to the British Olympic Association. The R&A confirm they are not part of this process.
UKS say professional sports such as football, tennis and rugby have also made no case. Rugby is also returning and, although the men's game is professional, the women's is not. They should surely make a case for support for Rio. UKS look at governance of any body applying for support but told me that a record of excluding women would not necessarily prompt refusal.
The BBC will brook no repetition of last year, when not a single woman made the short list for Sports Personality of the Year. The Beeb now has a nomination panel of 12, half of them women, including the chair Barbara Slater.
A former Olympic gymnast, and daughter of the former Wolverhampton Wanderers and England footballer Bill Slater, she is the first female director of BBC sport.
It's too late to initiate a female sports personality award for this year, but that should become a priority. Only 12 women have won in 57 years, with a half share for Jayne Torvill in 1984.