Sounds like from the article it was more a matter of corporate mismanagement than real issues with the tech or the idea of drone deliveries. I mean when you are hired data analytics folks through temp agencies and your managers have no understanding of UAV tech, what do you expect? Even the most promising program would fail with these handicaps.
It will be interesting to see what happens here. I noticed that WalMart has an executive speaking at this year's Commercial UAV Expo in Vegas. I don't think drone deliveries are going away just because Amazon UK tripped over their own shoelaces