Ever since the new MRT connection to the airport has been opened, Singaporeans love to hang out at the airport. Some families are reported to spend entire weekends there...
Apparently, they appreciate the variety of food and entertainment offered, good shopping, lots of things to see and last but not least, free aircon!
So, when you next travel through Changi, please step carefully so as not to disturb a family gathering or picknick. http://www.flyertalk.com/airports/ftairports_forum/smile.gif

I definitely agree with you. The mostly hang out in the viewing gallery during weekends and school holidays.