I am happy to notice that William L. Craig is less prevalent now in media than he was just a few years ago.I am convinced that debating him is not beneficial for anyone whose opinions differ from his, nor is it beneficial for almost anyone in the audience.
Several skeptics have pointed out that his debates basically only uses the atheist participant as a foil against which to present something that the believers in the audience will find convincing – it serves to reinforce their beliefs, since they won't question his line of reasoning, and no matter how convincing the atheist, they'll shrug his arguments off.
I think it's more insidious than just that - I think he is aware that his arguments are not convincing, and I think he is also aware that most of his fans in the audience are not educated enough to realize this.
In essence, they experience a convincing argument, and are left baffled as to why the opposition - the atheist - does not understand that these arguments are convincing. They then have to conclude that the atheist either is stupid or disingenuous – he must have some underlying, illogical reason to reject the argument of the apologist: he must hate God.
I really think the primary thing Craig achieves is to seed that kind of suspicion in the minds of his fans - it's a subtle method of turning Christians ever more suspicious and hateful against people who think differently.