One reason could be the use of microwave links for backhaul, which is cheaper, rather than fibre, which is faster but more expensive.
Oh I didn't know light travels faster than light. (unless more bandwidth = faster?)
Microwave is also susceptible to weather conditions.
They're perfectly capable of dealing with layer two packet loss and the only 'issue' you'd get would be ice/snow on the protectors, which doesn't happen very often in the UK.
Biting the hand that feeds IT
