So you are all a little bit thicker than you used to be, are you? When I say all, I obviously don't mean every one of you. I only mean those of you who are reading this and who also go to the theatre.

Because according to our (nationally and ethnically) most brilliant playwright, Tom Stoppard, theatregoers aren't as clever as they used to be.

Stoppard expressed this view after the opening at the National Theatre of his latest thought-provoking play, The Hard Problem, a work that addresses the intellect-taxing conundrum of whether the mind is in fact different from the brain.

He lamented that today's audiences just can't consume a play's ideas and cultural jokes in the way that they used to. They lack the intellectual koyech -my word, although actually a Yiddish term used by my mother when she can't open a jam jar.

Stoppard was later endorsed by one of our (nationally and ethnically) finest actresses Janet Suzman, and reinforced by another of our (only nationally) very fine actresses Patricia Hodge. Both have gone on record as saying that theatre audiences are much less clever than they used to be.

"People's attention spans are not the same," said Hodge referring to theatregoers, such as you. Suzman went further. "People…" (yes, I'm afraid you again) "don't understand literary and historical references any more… their education is not as wide."

Of course, they are not specifically talking about Jewish audiences. But if David Hare's observation is right - that theatre audience numbers generally decline after the first few weeks of a play's run because, by then, Jews have already seen it - then it follows that Stoppard et al are talking about Jewish theatregoers at least as much as any other kind.

If this is offensive, I shall stop using the accusatory "you" and will replace it with the less challenging "us" or "we." So, speaking as someone who has been a theatre critic for 14 years now, are we losing our theatrical IQ?

Certainly it has never been harder to get intelligent straight plays on in the West End without a seriously famous star to hang it on. Shakespeare generally doesn't get a look-in unless it has David Tennant in it. There was a time when the public flocked to see the new Terrance Rattigan because, well, it was a Rattigan.

And in New York - a city of obsessive Jewish theatregoers if ever there was one - it used to be the writers who put bums on seats, not the performers.

Now, if your play isn't a musical, wasn't once a popular film or best-selling book and doesn't have an attractive Hollywood star in it, you might as well put the script back in the drawer.

I'd love to blame the current generation of commercial producers for this. And I do. But that would be to let you - sorry us - off the hook all too easily. What producers instinctively like to do is not find the next successful show, but to copy the previous one. And as the previous one was probably a jukebox musical with a score plundered from the back-catalogue of a pop star, these shows have taken over the playhouses (that were built for plays) like Japanese knotweed.

Those shows that genuinely question the human condition or hold a mirror up to the way we live can now be found only in subsidised theatres because audiences – ie us – are just not willing to take a punt on the unexpected.

Admit it. When we go to a show we don't want to be surprised, we want to be fed exactly what we expect to be fed. This doesn't necessarily mean that we are less intelligent than we used to be. But it might mean that we are a lot less curious. And curiosity is after all the driving force of intelligence.

And so the theatre, once a place where we went to be inspired by ideas and challenged by argument is now too often a place for the placid, where we graze on the stage equivalent of easy-listening. And if Stoppard is right, it's all your fault.