I find his refutation of the proving-Islam-wrong-by-destroying-Mecca argument to be insufficient. The caliph, and the caliphate, are restorable; no permanent damage was done to their beliefs by its abolition. The destruction of Mecca would be a one-way trip and not reversible.
We need to cut the conventional nonsense and cut the throat (no pun intended) of Islam itself so that it bleeds to death. Whether it be peaceful or militarily, we all know the violence will continue so long as Islam is a major religion.
The ummah has huge death wish and Mecca-Medina are part of it. They know those cities will be turned to glass someday as a reposes to Muhammadan terrorism and they actually want this to happen. In the dark recesses of their minds.
Something like suicide by cop.
And Islamic faith will never recover if their bllshit Allah cannot protect his unholy cities.