What’s the point of having a Brexit debate between May and Corbyn?

I can see that there is a moral case for a General Election, as demanded by Jeremy Corbyn. An election which Corbyn would win, by some margin, I suspect. The government is inept, hopelessly divided, derided and May will not get the majority she needs to push her Brexit deal through the Commons. There is a strong practical as well as moral case for an election then. I get all that.

What I do not get is why this TV debate should be between May and Corbyn. If Corbyn had a clear line on Brexit then maybe. But he does not, he has been, on the issue, evasive to the point of obscurantism and even now I do not know what he wants to happen. In the Brexit debate he is a total irrelevancy.

If we are to have one of these fatuous debates it should be between May, a determined no dealer such as JRM, and a devout “deny democracy” campaigner such as Chukka Umunna or Tony Blair. The Labour leadership should be ignored.