I would not say the world sees it as a scam and neither would I say that it is a lack of interest but rather, I would say many people who have heard about bitcoin and are not indicating interest are just sceptical about it maybe due to their experience in the past with Ponzi, scams etc which made them to not put much interest but observing as events unfold it self.

I believe we all know that advertising is a key tool in getting a commodity to the consumers. If bitcoin is properly advertised im the sense that people are taught or told about bitcoin, I believe that Idea of seeing it as a scam would be dropped and people tend to take part in such activities when they see someone close or related to them doing it. That arouses their interest to learning and knowing more about it.