As Kate Molleson said in her review of Richard Jones's new production of Der Rosenkavalier in yesterday's Herald, the Scottish Chamber Orchestra's principal conductor Robin Ticciati probably did not expect his debut as music director of Glyndebourne opera in Sussex to be controversial in quite the way in turned out.

As she also noted, Richard Strauss's tale of prejudice and superficiality was proved to be bang up to date by the tone of the reviews meted out by the London newspaper critics.

They variously described Irish mezzo Tara Erraught as "dumpy of stature" (Telegraph), "unsightly and unappealing" (Times), "stocky" (Guardian), "a dumpy girl" (Independent) and "a chubby bundle of puppy-fat" (Financial Times). Other sopranos, her employers at the opera house and female journalists were quick to respond, and a right hoo-ha was brewed up on social media with accusations of mysogyny and body fascism being bandied about. BBC Radio 4's Today programme added a contributuion from Dame Kiri te Kanawa, down the line from New Zealand, who was able to add the wisdom of comparing photographs of Erraught on stage and off to declare that it was all the fault of her costume.

Leaving aside the fact the being able to suspend disbelief sufficiently to accept that an ample soprano is a dying consumptive has long been part and parcel of the business of watching opera, let us pause to consider just how "various" the opinions of those scribes visiting Glyndebourne from the London criticising bubble actually are. "Not very" is the clear answer, which might strike you as a little odd.

To single one out, here is Richard Morrison of The Times commenting on the furore on Thursday: "Whatever else opera critics may do, they don't compare notes at the interval... it's rare that we agree in print about anything."

This is plainly protesting too much, because the language used by the metropolitan critical coterie is far too similar for it to be a coincidence. The truth, dear reader, is one often observed by the Scottish critics when the London mob make their annual trip north to Edinburgh. They are all too likely to speak with one voice, and they are often saying something that baffles their Caledonian colleagues.

Opera critics are not alone in being guilty of this. West End theatre critics also appear to act in consort more often than is altogether healthy, and their critiques of shows on the Edinburgh International Festival and Fringe rarely show the diversity of opinion that you will find among writers in the Scottish media about the same shows.

I am not well-versed in mechanisms of the world of cinema journalism, a specialist area with its own bizarre codes of behaviour, but I am assured by those with a seat inside that tent that the London-based cinema critics display similar gang-mentality characteristics.

We know that the behaviour of the property market in London is a world apart from the experience of the rest of the UK, but that insularity is exposed by the limited - and unnecessarily base - vocabulary deployed by those whose fortunate job it is to analyse this highest of art forms.