That made a lot of sense to me, and I could understand much better why they would introduce McCafes. Thus I think that this is probably a smart move although a bit late...
But then McDonalds, I think, already sell more coffee than anyone else in the UK, so I guess they're converging from both directions.
So when Starbucks came with a poor product the only people who went were curious locals (who didn't return) and Asian students who liked the brand:
(Omad = one meal a day)
Similarly, they also sell very-high-sugar cakes and drinks.
Think you're right about Coca Cola re Starbucks, though perhaps they've stalled because their business has typically revolved around logistics / volume rather than brick and mortars...?