If you think that tearing orthodox interpretations of the Bible apart started with the Da Vinci code, you slept through any classes you attended on the Enlightenment -- not to mention any number of ancient heresies, pagan Roman polemicists, etc...
Most criticisms of the Bible are as old as the hills, and have been answered by Christians every time they come up.
What I can't figure out is why anyone who doesn't believe that Jesus is who Christianity says he is would think that it would matter in the least whether or not he was married and had children.
Jesus is of significance to the world because so many people have been utterly convinced that he was who the Church says he is, and because they believe that what the Church teaches about him is true. If he is not what Christians believe him to be, then he was an obscure failure of an itinerant Jewish preacher, then his blood-line is of no more interest than is mine, and no-one would have bothered to preserve or record it. It would certainly have no significance to future humankind, as the Holy Blood, Holy Grail people seem to think it does.
The whole Holy Blood, Holy Grail stuff has been around since the Middle Ages. The only explanation for it that makes sense is that it was a mythology that was concocted as part of some sort of subversive society pitted against the Roman Catholic church. It's power is that it took the incredible reverence for Jesus as God, and then read *that* back into a bloodline. The fact that this was completely illogical wouldn't faze the type of people who go in for "secret knowledge" and "secret histories" one bit. In fact, the kind of small minds that believe in that stuff thrive on logical fallacies.
Why would a "kingly" line be founded on a failed Jewish preacher? What claim would he have had to such a thing? Why would his bloodline have been of any significance? The whole thing is just too silly for words.
Believe that he married, died in obscurity, and that the Church created a whole fabricated mythology around made-up stories about him. That has some logic to it. Believe that he was the Son of God and the Messiah, and that what the Church passed down about him is true -- that makes sense. But believe that he was just an ordinary Jewish rabbi and that everything the Church said about him from the earliest centuries was a lie -- but yet that he also has some sort of cosmic significance that kingdoms would rise and fall over his bloodline? Give me a break...
I think that a person named Jesus did live & that he walked around his immediate surroundings saying that he was the son of God.
Someone doing this today would be 1/locked away or 2/ manage to get a lot of folks to drink Koolaid or 3/ go on Oprah, sell a few books & fade into obscurity.
But it was different times then. People were very into superstition, otherwordliness etc & so he picked up a large following.
The fascinating part of it all is the huge impact it has had on the history of the world. The religion that he started has had an enormous impact on history.
So, for many people, trying to track down some actual facts (outside of the Catholic PR manual...the Bible) is extremely interesting.
Will the discovery of Jesus' progeny amount to a hill of beans? No. But the study of the life of powerful people in history will always be interesting to many people.
You see, the line of Jesus is important because King David was a space alien, and therefore Jesus and Mary Magdalene passed superior alien DNA on to the Merovingians.