It's not surprising. Reading for pleasure was phased out of schools a long time ago and replaced by "Literacy" and Accelerated Reader where kids are tested on the books they read and have to finish them as fast as they can.
We have a neo-liberal school curriculum in the UK that only sees reading as a function of employment or cultural indoctrination (in the case of the statutory requirement to teach Shakespeare and that no non-UK writers are allowed to be studied at GCSE).
As an ex-English teacher I can assure you that’s the case. It changed in the 2016 reforms (when, among other things grades turned into numbers). It’s the same for To Kill a Mockingbird, another much-taught US text.
Some schools use Of Mice and Men as class readers in Year 8 and 9.