Who cares if they were producing goods for worship, or self, the point is they used more resources than their environment produced. Who can have the biggest statue? Who can have the biggest house, SUV? It's all the same end result. Easter Island was a small scale example of unsustainable consumption of resources, they ran out and their civilization collapsed.
The other Polynesian cultures weren't nearly as isolated. The Earth is our Easter Island, we have nowhere else to go for now, we should be working towards long term sustainability rather than short term individual gain.