This view is rare even among atheistic skeptics. Most scholars believed Jesus was a real person. The debate is whether or not all of the events in the gospels can be trusted. This author's argument seems to be essentially this:
1. The earliest testimonies of Jesus all declare him to be a miraculous savior.
2. Miraculous saviors can't exist.
3. Therefore, Jesus must never have existed.
But this line of thinking obviously begs the question: Why can't a miraculous savior exist? Yes, it is unpopular among academics to tout such things as possibilities, but there is nothing logically impossible about it. It's like saying the following:
1. Modern physics teaches that time slows down for objects moving close to the speed of light.
2. Time can't slow down! That's crazy talk!
3. Therefore, modern physics must be false.
(Funnily enough, I actually know people who think like this, but that's a whole 'nother story.)
The funny thing about his whole argument is that it actually leads credence to the fact that Jesus actually was who the Bible claims he was. He admits that the task of creating a "historical Jesus" apart from the 1st century writings has not been successful, but instead of looking at the possibility that maybe Jesus really was who the Bible says he was, he simply assumes Jesus must not have existed. If those are the two most logical choices, I know which one I believe. :-P