Harmonization is unfalsifiable — with enough ingenuity, anything reconciles
The objection
Watch what the method actually permits. If two accounts differ in number, the harmonizer says one is partial. If they differ in order, he says ancient writers rearranged. If they differ in wording, he says they preserve the sense. If they differ in the event itself, he says it happened twice. There is no possible pair of texts these moves could not absorb, and a procedure that cannot fail is not doing any work. Compare it with how the same reader treats a book he does not revere — the Qur'an, the Book of Mormon, a rival gospel — where a discrepancy is simply an error and no ingenuity is deployed at all. The method is not a method; it is a conclusion held in advance and dressed in historical clothes.
The response
This is the strongest objection on the page and it is right about a great deal. Unlimited harmonization is worthless, the double-occurrence move is where it usually goes bad, and the double standard the objection describes is real and common. So the reply cannot be a defense of the method in general. It has to be a criterion. Here is one, and it is the same one you would use on any ancient source: a proposed reconciliation is legitimate only if it is independently plausible on what we know of how such documents were written, if it does not multiply events to survive, and if it makes some claim that could have turned out false. By that test, most of the tomb differences pass, because we can watch other writers of the period compress and select the same way — the practice is documented outside the Bible and was not invented to rescue it. By that same test, the Judas reconstruction is weaker: it is plausible, but it is a guess, and this page labels it one. And by that test the Quirinius proposals do not currently succeed, which is why the page says so out loud. A method that reaches different verdicts on different cases is a method. If every case on this page came back resolved, the objection would have won.