I used to freelance for my local BBC Radio station at the start of my writing career.
The overwhemlimg attitude that pervades the organsation is that they are above everything and everyone else.
I honestly believe that the actual concept of 'spending money' does not feature in the daily lives of BBC employees - they simply ask, and it is given.
Meals, hotels, taxis, trainfairs, airfairs, houses - they all just appear as if the fairies bring them, so the idea that they are actually spending money which does not belong to them, but with which they are entrusted to spend properly, simply does not occur to them.
Until a proper system of accountability - starting with the Trustees and working down - is implemented, then this situation will continue.
Sadly, the people who would be able to enforce such a system, are the MP's, and it is utterly familiar to them becausre they live and act and spend in exactly the same way, so no need to change anything as far as they can see.