[ZeroMinx]

Is that really Airbnb's fault?

Airbnb is the service provider in this case, but there are other companies with a similar service, or the neighbour could let it out personally to other people.

Assuming the neighbour is subletting illegally as you state, surely that's where the problem lies.

[XJOKOLAT]

It's not airbnb's fault but if found to be true why wouldn't airbnb simply de-list them?

It's like being a CEO and finding out that one of your employees or contractors is engaging in illegal activity. They get fired. Simple.

[ZeroMinx]

Sure, if Airbnb have been given proof that the subletting is illegal, they should remove the listing.

But my point is that doesn't really solve the problem. What should be sorted is the fact that this person sublets the flat illegally.