I heard once that it’s because of the connection between the Written Torah and the Oral Torah. They’re intertwined and everything in the Oral Torah has a source in the Written Torah, but that’s only true when the Written Torah is the way it’s supposed to be written.
Forcing a translation into Greek was effectively forcing the detachment of the Oral Torah from the Written Torah, and saying you can have the Written Torah as a nice cultural artifact without the depth and significance that the Oral Torah brings.
Which, in light of Chanukah, was kind of a Greek thing to do.
Hope that’s helpful!