I'm here to back up Luiz. Brazil (and Thailand and Vietnam) has a great variety of different types of bananas, many of which I personally think are better (in texture, sweetness and smell) than the standard US/EU banana. They don't seem to have any trouble distributing them, selling them or eating them in large quantities.

I do not know anything about the details of banana cultivation: whether it's intensive monoculture or closer to wild growth (I suspect the former) but I can see that our standard bananas have to satisfy several criteria: they have to respond well to picking while still unripe, so that they can endure long travel/storage/sheft lives, they need to be reasonably uniform, because supermarket customers have been shown to respond well to uniform size and colour in products, I understand they're straighter than other varieties because this facilitates packing and they're unusually resistant to rough handling. All of these considerations come before the subjective judgement of how they taste or what their mouthfeel is like.

I can easily imagine that there is no other variety of banana out there that does all these things as well as the Cavendish - but consider: supermarkets are willing to ship all sorts of other fruits that don't travel as well and have shorter shelf lives. They tend to be a little more expensive and some of them are more seasonal, but they still find their way to us. It might be that the demise of the Cavendish will actually lead to more varieties of banana becoming available to Western (or Northern) consumers, at a slightly higher price, fresher and closer to ripeness, with an overall increase in quality, quite possibly grown by smaller cultivators. That doesn't sound so bad to me.