Corbyn’s speech confirmed the main argument of his critics

Of all the speeches Jeremy Corbyn could have made, this was the most predictable and the most useless. There was no thematic content, no idea unifying what he was saying, no quality in delivery, no attempt to speak to the public outside the hall, no plan for the future and no sign he is prepared to work with the media to communicate his appeal more widely. It was the speech of someone who either doesn't care or isn't capable of speaking to anyone outside of his immediate supporters.

Corbyn's first and worst mistake was to spend so long attacking the media. He started by mocking the inane tabloid attacks he's been subjected to, from Chairman Mao bicycles to his supposed support for a meteorite to destroy the earth. This was actually quite funny. It was the right tone – some gentle poking. It could even have been a moderately effective tactic discouraging the more hysterical press coverage.

But then he returned to the theme halfway through the speech with a lip-spittled attack on the "commentariat". One wonders what he is trying to achieve with these asides, except to alienate the very people who will be delivering his message to the public. Corbyn evidently views the media as one homogenous blob, from the Sun to the BBC and everyone in between. He has no interest in accommodating it, or building a relationship with parts of it, or seemingly doing anything but attacking it. It was a real head-in-hands moment for those who think he is capable of doing interesting and influential things on the public stage. He is attacking the messager and then acting exasperated when they fail to communicate his messages sympathetically.

The rest of the speech was a shopping list of views and principles, from refugees to steel factories, parental leave to online trolls. It was quite the hit rate, veering wildly from one to another with barely a pause for breath. The trouble was that there's no storyline, no central idea to think over, nothing to grapple with. It quickly becomes boring watching a man reel through his pet concerns.

Some of these areas could prove profitable down the line. His demand that David Cameron step in to lobby Saudi Arabia to stop the execution of Ali Mohammed al-Nimr and cancel the Ministry of Justice's contract with their penal services could be very effective. How can a British prime minister respond to that sort of pressure? It's a potentially damaging attack on the Conservative leader which speaks directly to Corbyn's concerns and the British sense of decency and fair play.

The same could be said for his demand that the government step in to save jobs at Teeside steel factory. The public are ready and willing for exactly this kind of left-wing intervention, where leading politicians do more than just whimper about their inability to interfere with the market. But as soon as it was raised, the issue disappeared from view, to be replaced by something else.

There was a policy on parental leave for the self-employed which could either win over a new layer of supporters or provide the Tories with another very effective economic competence attack. It was hard to tell, because as soon as it was alluded to, we were onto something else. There was a mention of academies being returned to local authority control, suggesting Labour would now oppose them as official policy. But again, it was gone as soon as it was mentioned.

There was, to his credit, an honourable moment in which Corbyn robustly rejected the abusive manner in which much online debate is conducted. It was brave of him to risk alienating his own cyber supporters and the gifs which will inevitably follow of the section will prove a useful riposte to those trolling in his name. This principled moment won him perhaps his longest round of applause and he deserved it.

Indeed, many people in the hall seemed to love it. The standing ovations were not instant and springy – the behaviour of people who know what's expected of them. They were hesitant, uncertain and gradual. Completely natural, in other words. The great division of perception – between those enthused by his amiable, eccentric, dishevelled style, and those baffled by it – continues.

But speeches are not just shopping lists of demands. They are supposed to communicate something – an idea, a tactic, a personality, a plan. Anything. This was like scattered sand, ideas without any discipline to rein them in.

The failure to communicate an idea or an argument wasn't just a technical or presentational fault – it was a failure of ambition. It showed Corbyn had no intention of speaking outside of the hall, or even to the sections of his party which do not trust him. Fundamentally, this was not the speech of a man trying to convince anyone. It was for his people alone.

Every so often a glimmer of political ingenuity would emerge, like the argument for a powerful military to carry out humanitarian work. They offered hope that someone somewhere within Corbyn's inner circle might be imagining ways to round his demands with the expectations of the British public. But generally speaking this was as unimaginative and unambitious as political speeches get. It was a speech which seemed to confirm the main argument of his critics – that he won't be able to reach outside of his supporters and speak to the country at large.