it is not inconceivable that, as time passes, the ignorant will grow ever more convinced of his sanctity, and that their excessive veneration will prompt them to pray toward him if the grave lies in the direction of the qiblah within the mosque. Such conduct will ultimately lead them to disbelief and polytheism.”
He then marshaled several quotations that advance this very rationale, citing a number of scholars—among them Imām al-Shāfiʿī, whose words we have already reproduced (p. 42). After that, the same author adds (pp. 20–21):
“The aforementioned rationale has now disappeared, for faith is firmly rooted in the hearts of the believers. They have been reared upon pure tawḥīd, upon the conviction that no partner exists alongside Allah Most High, and that He alone creates, brings into existence, and directs every affair. When the rationale ceases, the ruling that rested upon it likewise falls away—namely, the disapproval of building mosques and domes over the graves of the saints and the righteous!”
I say in reply: the proper rejoinder is the proverb, “First set up the throne, then engrave!” That is, first establish that the sole rationale for the prohibition was the fear you have mentioned, and then prove that this fear has truly vanished. Achieving that, however, is like stripping thorns from thorn-bushes!