Answer
They are not wrong—this has a historical background. Earlier, there was no restriction, and many devotees used titles like “Divine Grace.” In fact, until around 1993, it was generally accepted to use “His Divine Grace.”
Later, the GBC passed a resolution that this title should not be used broadly, to maintain clarity and avoid confusion. Before that, it was quite common—you can even find official documents where titles like “His Divine Grace” were used for multiple leaders. For example, in some older letterheads, you would see “Founder-Ācārya His Divine Grace A.C. Bhaktivedanta Swami Prabhupāda,” and below that, other leaders also addressed with similar honorifics.
Over time, however, there was concern that too many such titles—like “Prabhupāda,” “-pāda,” “Goswāmīpāda,” “Ācāryapāda,” “Śrīpāda,” and others—were being used widely, which could create confusion or dilution of meaning.
So the GBC eventually decided to standardize this and restrict such usages—particularly reserving “Prabhupāda” exclusively for Śrīla Prabhupāda. You could say it was a kind of corrective step, taken to bring consistency and avoid misunderstanding.
It’s an interesting piece of history showing how practices evolved over time.
