Eh, management culture perhaps?
I know that a lot of customer service reps trained in the UK are under huge pressure from management to limit the amount of returns or free replacements they give out. I had a similarly poor service from Nike when the Fuelband was a thing, and once again the store manager was at best oblivious and at worst deliberately trying to fob me off ('You can't return it once you have used it for data privacy reasons' - this being despite the fact that I had performed a factory reset, was well within the return period and had quoted the website's 'no quibble' returns policy - if you ask me they were under pressure to reduce returns of the Fuelband - also note I still wanted one, just a different size).
So yeah, cultural? I don't think so, I think if Apple's store managers in the UK did not make their staff fear consequences if they accepted too many returns or gave out too many good-will gesture placements, we would have a much nicer experience in the UK. As it stands, Apple's retail HR seems to hire ******* managers who are used to bad management culture from previous employers. For them it's all about targets and not about customer experience.