On one of the days we spent in Bonaire, the roads near the courthouse were closed for a big criminal trial. It wasn't a big enough trial to yield any Google results but big enough for all the locals to know about it. A cab driver told us that it involved people from Curacao that were accused of murdering a third person from Curacao a little while back. Apparently, people from Bonaire don't do murder; it's those bad seeds from Curacao bringing down the hood. We had also heard rumors that people in Curacao aren't as friendly as in Bonaire.
When we got to Curacao, it did seem true that the local people in Willemstad weren't quite as friendly as in Kralendijk (Bonaire). But Willemstad is a huge metropolis next to Kralendijk. It's an almost universal truth that people who live in big cities aren't as friendly as those who don't. It's self-preservation--otherwise you would spend all your time greeting everyone. Curacao has industry and business that isn't just tourism. Of course, the population of the whole island is still less than 150,000 people, so it's all relative.