Wearing masks

I took a flight from Singapore to Vancouver. The only people in the plane wearing masks are  the flight crew and a few Singaporeans. The other passengers did not consider it necessary to wear masks. Were they irresponsible or unaware of the risk? 

I do not think so. I think that they know the risk and have decided that it is the risk is too small to take these precautions. Singaporeans tend to over-react.