Re: Or maybe...
'Purely Marketing'? Not quite. It's also public perception. If it wasn't important, they wouldn't have put up the bloody thing in the first place. I imagine the perception among the general public is one of nothing too important, but the fact sticks in there that BT is associated with silly meaningless error messages on a display. The next time there's something silly and meaningless on a BT hoarding, it'll reinforce negative thoughts of the brand.
It's hugely important: It's a bloody big tower in the centre of a very big city with the words 'BT' on it and some utter nonsense scrolling underneath!