How noble was this decision to abandon the RSC?

These directors know how to turn the stage into a world of magic. Only they won't do it for 'straight' theatre

"Exit director stage left, in high dudgeon" is, I suppose, one summary of Adrian Noble's decision to leave the Royal Shakespeare Company after his radical reform plans have been slated from every side of the media divide and half the theatre grandees.

But then "exit stage right, bearing lucrative contracts to produce musicals in the commercial theatre" could be equally true of a director who announces his resignation after taking three months off to produce Chitty Chitty Bang Bang on the London stage and waiting to see the reviews (good to excellent).

If it is the latter reason, then he will join a distinguished line of directors of state-subsidised theatre who have made their reputations at the cutting edge of theatre and then embraced the rewards and glamour of the commercial. Trevor Nunn got himself in an awful lot of trouble for earning huge sums from musicals such as Cats when he was at the RSC, a line he has continued at the National with My Fair Lady. Richard Eyre left the National with a commercially successful film, Billy Elliot. Sam Mendes is off in Hollywood. Stephen Daldry of the Royal Court is doing his own things. Only Jude Kelly of the Yorkshire Playhouse seems to be moving from the state sector to pursue a new experiment in theatre.

And why shouldn't they all seek more lucrative careers? It is a peculiarly English form of artistic envy to resent the success, and the rewards, of artists, preferring them to live in penury for their art. To seek fame and fortune in America is somehow regarded as a sell-out.

Forget it. The director is today's impresario; the arts world is global. Success is measured in global terms and fees are determined by how many customers you can get to fork out £20-50 for a seat. The old idea that theatre directors were the heads of troupes that worked their way through the repertory through thick and thin was bound to be corrupted by a world in which the director could catch a plane to Geneva or San Francisco, spend three or four weeks rehearsing a cast and then walk away with a fee of several hundred thousand pounds and a share of the take.

And yet the idea of a performing troupe is actually what remains the raison d'être of the great national theatres, not only here but also all across the Continent. And it is at the heart of the debate going on not just about the RSC's plans but Trevor Nunn's ripping up of the Lyttelton at the National as well. The Royal Shakespeare Theatre was revivified after the war to provide a company corps of actors working together to present the works of Shakespeare and the solid corpus of classical theatre. The National Theatre was founded to present a continuous repertoire of old and new and to keep it constantly refreshed.

Bliss was it to be alive for Peter Brooks's revolutionary production of A Midsummer Night's Dream and Marat Sade and very heaven to be there the early years of Laurence Olivier and Ralph Richardson's playing of Ibsen and restoration comedy at the National. It may have wowed the establishment and the middle classes but it also opened a whole new world to schoolchildren and students like myself, queuing up for the gods.

It is this inheritance that is now under threat from Adrian Noble, and the attacks of Richard Eyre and Trevor Nunn. The old theatre was fine for its day, they believe, but the audience of today no longer believes in the proscenium arch; it wants open spaces. It has no desire for spectacle, preferring the intimacies of the small stage more attuned to an audience brought up on television. They don't believe in company troupes because actors and actresses are, like directors, unwilling to commit themselves for long when they can earn more money jobbing about. And they don't care for middle-class, middle-aged audiences because the theatre is supposed to be appealing to new audiences, young people and different or ethnic groups (or so the government edicts would have it).

Hence Adrian Noble's desire to tear down the proscenium-arched Memorial Theatre in Stratford, to leave the regular London theatre and to recreate the company as ad hoc groups of touring actors going into schools and new spaces around the country. Hence also Trevor Nunn's decision to replace the Lyttelton stage of the National with smaller theatres for a programme of new works by young authors requiring only a few actors each.

All very trendy – and there is nothing quite so trendy as the arts world seeking "radical restructuring". But it's not at bottom an act of modernisation. It's not that the directors in charge of these programmes really believe the old theatre is no longer relevant. It is that they cannot face the challenge of making it relevant.

Shakespearean theatre, it is true, is not a theatre of the proscenium arch. But that arch was the form of comedy and tragedy for 300 years from Vanburgh to Tom Stoppard. Dismiss it and you dismiss the likes of Goldsmith and Wycherley and Sheridan. Which is precisely what the RSC and the National have done. Where do you see works of real genius such as She Stoops to Conquer or The Rivals? Not at our national theatres but in our local ones – at Salisbury and Sheffield.

As for the tragedies and the magnificent tradition of serious drama, directors have preferred to turn the great symphonies of King Lear and Tamburlaine, Schiller and Ibsen into chamber plays, to be seen in a small space as stories of particular relationships rather than the remorseless drive of the universal themes of ambition, imagination and remorse. Peter Brooks's productions of Lear and other Shakespeare, the most electric I have had the privilege of seeing in my lifetime, were at the Memorial Theatre in Stratford and the Aldwych in London, the most conventional theatres possible.

If you're starting with a new theatre, by all means create flexible space as the National did with the Olivier and Chichester with its festival theatre. But don't blame the building for the failure to summon up "the vasty fields of France" on the cockpit of the conventional stage. For Adrian Noble to push for the rebuilding of the Memorial Theatre smacks not so much of radicalism as repainting the drawing room for lack of any better idea of what to do. That and the apparent availability of lottery funds – a pot of money which has done more to harm the performing arts in Britain than any other single development.

It's not as though there is any lack of small spaces for new work. The Bush, the Tricycle, the Gate and Latchmere in London and a host of companies in Newcastle, Leeds, Manchester and every university town are performing and commissioning the kind of work that Trevor Nunn is seeking for the National. And they are doing it better for the reasons that have always thrived in the performing arts: committed groups reaching to produce what they believe in. There is simply no point in the national theatres doing the same work more expensively when there is the whole patrimony of the theatre to be kept alive and revivified and a whole world of large-scale theatre to be explored.

Adrian Noble, Trevor Nunn and Richard Eyre know perfectly well how to turn the stage into a world of magic and drama. They are already doing it with musicals in the West End. Only they won't do it for the "straight" theatre. What is good enough for their purse is not apparently good enough for the people.

a.hamilton@independent.co.uk