John Gielgud once said he sympathised with critics. It must be awful, he felt, to constantly have to review the work of artists one didn't like. Well, that issue has recently come to a head in New York. Charles Isherwood, one of the New York Times's drama critics , has formally announced that he will no longer cover the plays of Adam Rapp, not even with a shroud, since he has cordially disliked most of them over a 10-year period.

I understand Isherwood's point, but I still think he is wrong. Obviously critics, like everyone else, have prejudices against certain theatrical forms or even individuals. Nearly 30 years ago the Guardian asked me to write a piece about my own which – at the time – included puppets, mime artists and allegorical works about characters called The Man, The Woman or The Lavatory Attendant. The result, I recall, was a rash of invitations to attend puppet and mime festivals, everywhere from East Anglia to Liege, in an attempt to achieve a Pauline conversion. And, with time, I hope I've learned to overcome what was once a myopic prejudice. I remember sitting spellbound before a puppet version of Shakespeare's Venus and Adonis at London's Little Angel theatre, and the expressive power of mime has been brought home to me by a host of companies, including Complicite in its earliest days.

In short, I think it's a mistake for a critic ever to bring the shutters down. In so doing, one denies oneself the possibility of a change of heart. Admittedly, there are times when it's tempting to adopt avoidance-tactics. I can't say I will rush in future to the work of Italian director, Romeo Castellucci, whose last piece was based on an old man's uncontrollable bowel movements. I also feel that the jukebox musical, consisting of raids on artists' back catalogues, is becoming an exhausted form, though paradoxically I did much enjoy Million Dollar Quartet. But I suspect that a severe cold may prevent me attending any upcoming adaptations of Jane Austen novels which compress her plots while sacrificing her attendant irony.

You can, however, discreetly absent yourself and ask a colleague to review without making a great fuss about it. I also think it was an error on Isherwood's point to publicly proclaim his boycott of Adam Rapp's plays: it denies any shift in attitude on the part of either critic or artist. I was, in fact, asked two years ago by one British writer-director to stay away from his work: a request I politely declined, since I'm eager to see what he does next. I've also had the odd run-in with the director of a popular London venue who is convinced I am rootedly hostile to his theatre and its work: I, naturally, think my criticisms are rationally justified rather than based on prejudice. But it would be madness on my part to say I will never darken his doors again. One of the key qualities in a critic is the endless capacity to be surprised. And, for saying that he will never again review a dramatist he dislikes, Isherwood has let the side down and deserves to take the Rapp.