This week, I will not go to the library.

I did not go to the library last week either, or the week before that. I have not borrowed from a library for 25 years. The one I used as a boy in Aberdeen has been pulled down and is now a field; many more in the city and across the country are threatened with closure. But I'm not upset by any of this; I do not cry over what's happened or bemoan the end of libraries because they are based on an idea that is no longer working.

The orthodoxy says otherwise – and it's an orthodoxy delivered with aggressive certainty. Libraries do all kinds of wonderful things, say their supporters: they promote justice, literacy and health, minimise social division and, these days, provide free downloadable books and a coffee and a bun as well. This diversification is presented as the solution to the decline of libraries, but is, in fact, the problem: going into a library now is like going into HMV or Woolies just before it closed. It is a model that is confused and unclear; it no longer knows why it is there. And as for free downloadable books in libraries: like Kindles in Waterstones, that is like inviting a pussy cat into an aviary – the route to certain destruction from within.

I can understand why libraries have gone down this road – it is partly an attempt to survive, but it is also a deep-seated denial about how libraries are used. Look at the list of most-borrowed books and you can see for yourself. You'll have to go way, way down the list, below the top 100, before you reach any non-fiction and even then it's Jamie Oliver and Nigella Lawson. The list is dominated by the likes of Lee Child and James Patterson and bloody, badly written crime thrillers. Next year, for sure, 50 Shades of Grey will also be on the list. It has nothing to do with literacy or minimising social division. It is entertainment– that is all – which raises a question: why are we paying for it? Everyone has the right to read 50 Shades or Martina Cole or Danielle Steel if they want to, but they do not have the right to read them for free.

That is the issue that should be at the heart of the debate about libraries because that is how they are used – and the discussion of the future of these institutions should be based on what they are, not on what supporters think they are. For a long time, no-one has felt able to say this –it is been the silent truth – but now, at last, some iconoclasts are beginning to emerge, the most notable of whom is the writer Terry Deary.

Deary, who is most famous for his Horrible Histories books for children, broke cover last week and drew anger and excoriation when he suggested libraries have had their day. Part of the reason he said this was his worry that book lending undermines the income writers get from sales, but much more important was his point about subsidised entertainment. "What other entertainment do we expect to get for free?" he said. "We've got this idea that we've got an entitlement to read books for free."

Challenging this idea will give us a plan for the future – one that might even save a few libraries from closure. At the centre of the plan should be an end to the lending of fiction on the basis that public subsidy should be for the public good, not for whiling away a few hours with a cheap thriller. As for the other peripheral issues the pro-library campaign sometimes raise, such as access to the internet or literacy, there are more effective ways of dealing with these issues than paying for big buildings that cost big money to run. If you believe access to the net is a right, for instance, there may be a case for some subsidy of broadbrand along the lines of subsided television licences. As for literacy, the best place to tackle that is in school where the problem starts.

All of these changes – but particularly the end of the idea of entertainment for nothing – would help libraries to focus on what they were set up to do in the first place: promote knowledge, provide a shared source of education, but above all offer a quiet place to read and think. We'll just have to buy our coffee and buns somewhere else.