We don't know. Redford says you can't create a narrative (at least for the first 5 years of Amenhopsis IV's reign) as there's nothing to look at as it was destroyed. Horemheb obliterated the whole area, so it's only accidental information that seeps through, and so partial reconstruction is all we have.

We could speculate that this is a theologically motivated, as Akhenaten swapped the syncretic, polytheistic cult for an exclusive monotheistic one, and avoids the Heliopolitan vs Memphite vs Hermopolis trichotomy by settling for neither of them. Because of his centralizing of cultic worship, the other temples suffer, their priests sent to work in the quarries. This is probably the most obvious answer, but we don't know exactly why he decided this.

There's a case to be made that it could be bureaucratic. Akhenaten rejected most of the previous administration of his father and introduced a new group of men. Redford suggests he could have been kept in the background until his ascension, which explains why he replaced everyone - nobody at court knows him and he knows nobody. Rather than be beholden to a group of unknowns, he (arbitrarily?) makes his own way.

Either way, there's not a lot to go on.