First of all, nobody is arguing that this “has to be” the family tomb of Jesus. The person who wrote the article knows that but set up a straw man anyway.
The combination of names in the tomb is quite unusual, and it would fit with the names in Jesus’s family. So that is at least a suggestion that this may be the tomb.
I read the book. (Fascinating, whatever you think of its theories.) Nobody is claiming that Jesus didn’t exist. To make that claim would undermine the entire thesis, wouldn’t it? Yet the author of this “article” claims that this is what is being claimed.
The Nag Hammadi Gospels do not play into the theory at all, as this author knows. And he is likely wrong about their dates. But we know well that the Bible we have has been substantially edited and altered along the way.
They adduce evidence from the very beginning of the book, contrary to this writer’s claims.
There is much more. But I want to keep this post short enough that it will actually get read.
The “Jesus tomb” argument presented in the book has weaknesses, but so does the refutation. There are certainly indications that it may be “the tomb.”
Again, an unmarried 30-ish Jewish man in that place and time would have been remarked upon and noted. Does that prove the theory that Jesus and Mary Magdalene were married and had kids? No, but it does tend to buttress it. There are little things that hint at it through various writings.
And if it is true, it has no real effect on who Jesus was (or wasn’t) and what he taught. I do not understnad why it so upsets people.