That's part of what makes this a compelling article. Because of the quakes that caused the islands to dip a bit, the flooding started relatively abruptly. If sea levels rise faster than we expect, this might become a pretty common scenario. Between you, me, and anyone else reading this, I'm actually not that surprised the people on these islands are staying. Humans are pretty resilient and can survive under so many conditions that can be considered less than ideal.
That said, I think as situations where communities are facing hardship due to climate change start cropping up more and more, we need to ask some very important questions. Are people staying because they genuinely want to stay, or because there are too many barriers to relocating? If there are barriers to relocating, we need to figure out what they are and what we can do to help address them. If people genuinely want to stay, then we need to look at the challenges that will face them if they do and how some of them can be addressed. For example, for this community here, the flooded houses, the floating waste, and the hampered ability to grow food in the community are all issues that are cause for concern, but also ones that can probably realistically be tackled with the right knowledge and resources.