People often ask what point would be served by devolving the power of broadcasting to the Scottish Parliament. After all, we don't want political control of broadcasters, and isn't the BBC a UK institution? What difference would a bunch of Scottish politicians on a committee make to programme standards and service to the public?

Well, part of the answer is clear from the experience of the Scottish Broadcasting Commission which publishes its report today into the future of public service broadcasting in Scotland. In one sense, the final report - calling for a dedicated Scottish digital TV channel - is secondary to the impact the commission under Blair Jenkins has already had in the year since it was set up by the Scottish Government. Just switch on to any network news bulletin and you'll hear it. Scotland has suddenly started to figure in the BBC's London editorial agenda in a way it never has before.

In the past few weeks I've heard informed coverage on UK news bulletins of Scottish issues such as council tax, Titians, licensing laws, even the Highers exams. Last week's legislative statement in Holyrood wasn't nearly as significant as last year's, but it was nevertheless given important airtime on UK output. The BBC discovered it was missing a lot of real news in Scotland.

This is welcome, a tribute to the BBC and an object lesson in how to address a grievance in a democratic culture. BBC bosses in London listened to what had been said by and to the commission. When it was made clear to them that the network news agenda has been "hideously White City" - as confirmed by a report from Professor Anthony King, which recorded a complete absence of coverage of Scottish health and education in network bulletins in a four-week period - the BBC responded. It reprogrammed its producers to recognise Scotland's existence.

And it isn't just on network news that the Scottish Broadcasting Commission has had a profound impact. A matter of months after its investigation began, the Director-General, Mark Thompson, came north to Pacific Quay and announced a tripling of the value of network commissions from Scotland. He accepted that the BBC had fallen down badly in allowing the number of programmes from Scottish producers to dwindle. This is unalloyed good news and will provide a lot of high-value jobs.

However, more commissions for London will not address the number one issue in Scottish broadcasting today: the quality in BBC Scotland output. Much of what it produces for Scottish consumption simply fails to match up to the standards required of a national broadcasting service. This will become a crucial issue if the commission's main recommendation is adopted and the case is made for a dedicated Scottish television channel.

I can already hear the moans from chattering Scotland threatening to leave the country if they get wall-to-wall BBC Scotland on the telly. This is unfortunate, because there are a lot of very talented journalists and programme-makers in BBC Scotland working in an acutely demoralised organisation. Many others have left or gone south. The problem with BBC Scotland is not the people working for it, who are eminently capable of making excellent programmes. The problem is a lack of editorial ambition coupled with a chronic lack of funding and a culture of managerial complacency.

You could not expect BBC Scotland, as it is constituted and financed, to run a proper national television service. Which doesn't mean a dedicated digital channel is a bad idea. After all, the BBC is launching a Gaelic TV channel next month, and what is good for the Gael is surely good for the rest of us. Once the analogue service is scrapped in 2012, we will be in a different broadcasting world. That might be the time to refit Scottish broadcasting to match the new constitutional reality in Scotland.

But the benchmark has to be quality. For this to improve, BBC Scotland has to face up to reality. It must stop congratulating itself and start fighting to become a national broadcast service worthy of the name. Above all, it has to stop being defensive and hostile to criticism. Former colleagues tell me that I am now persona non grata on BBC Scotland as a result of evidence I gave to the commission. This is faintly ridiculous - like having a fatwa taken out against you by the Ramblers Association - and I mention it only for what it reveals about the vindictive cronyism that pervades much of BBC Scotland middle management. Self-delusion, too, because the comments I made largely came from BBC Scotland producers who are not allowed to talk openly for fear of their jobs.

Speak to anyone at programme level in BBC Scotland and you will hear complaints about a culture of editorial mediocrity, about chronic under-resourcing of programmes, a lack of imagination and ambition. Many highly able broadcasters are in a state of near despair at the lack of direction. Management at BBC Scotland know this - a recent internal staff survey revealed widespread discontent about the management's creative bankruptcy and its failure to communicate a coherent vision. Morale in BBC Scotland will not improve just because it freezes its critics off Good Morning Scotland.

Which brings us back to accountability, the essence of democracy. After the Scottish Broadcasting Commission shuts up shop, someone has to keep a beady eye on Scottish broadcasting. The proper body to do that is the Scottish Parliament. At present, Holyrood is specifically excluded, under the Scotland Act, from having legislative oversight of broadcasting. This is like saying that the Scottish Parliament cannot be trusted to handle this responsibility, which is a metrocentric attitude that is neither tolerable nor practical. Holyrood supposedly has oversight of the creative industries in Scotland, and yet not of broadcasting, which is the key creative industry. Such constitutional ring-fencing makes no sense.

Devolving broadcasting has nothing to do with imposing political direction over broadcasters. Labour MPs say Alex Salmond will start writing the BBC Scotland news bulletins if Holyrood gets control, but this is just scaremongering. Westminster has control of broadcasting, but that doesn't mean that Gordon Brown tells the BBC what to say in its news bulletins. There are important institutional bulwarks to prevent it.

I'm sure devolution of broadcasting will happen. It is a constitutional anomaly and will be addressed as part of the reassessment of devolution being conducted by the Calman Commission and the National Conversation. The SBC has started the job of reforming Scottish broadcasting; but it should be down to parliament to finish it.