Are they ashamed of them? Are they ashamed of the performers?
Are they worried that they will lose the argument?
Or do they think that in the cold light of day, watched on Youtube by thousands, the so-called benefits of the union will be shown, as the guy on the video indicates, to be a pile of Blethers Together?
My leaflet from the UK government came through the door this morning, and will be going back this afternoon.
It is a mixture of generalisation, meaningless platitude and downright lies.
Still, I look forward to Mr Salmond and Mr Darling debating with one another live on STV.
Of course there are those who have suggested that Salmond has backed down.
And it does indeed look like that. He wanted to debate with the prime minister and has found himself instead being relegated to debating with a part time, opposition backbencher who used to hold of "one of the great offices of state" as Britain likes to call the people at the top of their governments.
But Cameron won't debate for various reasons, depending on who you ask.
Some say it's because he knows his unpopularity in Scotland would result in more people supporting Salmond out of sheer hatred of the Tories and the Eton Toff himself.
Some say that it's because he thinks himself, and his great office, as being above debates with mere regional functionaries.
Some say that he simply isn't knowledgeable enough to debate on the subject and knows he would be roundly beaten.
He, on the other hand, says it's because it's nothing to do with him...he's not Scottish and he doesn't live in the country... which is strange considering the fact that he is Scotland's prime minister, not to mention the number of times that he has intervened in the topic when he was not face to face with the first minister, and how he has persuaded world statesmen including the American and Chinese presidents to get involved.
Actually, I'm not sure why Mr Darling agreed to playing substitute to Cameron. It seems almost like he's been set up to take the blame if, or when, it all goes wrong. Cameron knows that having someone else do the dirty work will mean that he can pass the blame.
Despite his once being a lawyer and an advocate, I don't honestly think that Darling is equal to taking Salmond on in a debate, at least on on this subject. Labour appears to think that he is a superb debater absolutely on top of his brief. But I'm dubious. Under pressure, he speaks too fast, stutters, says "you know" over and over again and he contradicts himself.
Salmond, like him or loathe him, is a pretty neat debater. He never seems to get flustered and remains always polite even when up against people like Lamont and Baillie, who would try the patience of a saint with their stupidity and their lies. Above all, whilst Alistair is relatively new to the independence debate, for Alex, it is a life's work. There's not a lot he doesn't know about it.
Added to that, and perhaps most importantly, Alex is the leader of the government that will be in power on the 19th of September, and whatever way the referendum goes, he will have a leading voice in the way that negotiations with the UK go.
Alistair is a back bench opposition MP. He won't be in power anywhere. Alex will be able to use that in the debate.
Following had on the heels of the referendum UK general election campaign, where, in a tight contest *between an incredibly unpopular Tory government and a Labour party led by a man that his own side think is weird, and which has very few discernibly different policies from the government, every little point scored will count.
It will not be in Cameron's interests to abide by promises made in the heat of a live tv debate, by a member of the party that he is trying to defeat.
*I suppose, in the interests of equality, I should add, "and a Liberal party..." whose members are deserting them in droves.