The man was almost certainly ethnic Chinese - they seem to believe that Singapore belongs to them, along with the rest of Southeast Asia.
From experience (and it appears the locals agree) the worst tourists are large groups of Chinese. Rude, loud, obnoxious, constantly spitting on the ground and you just don’t want to be in the same restaraunt. Literally laughing, yelling, chewing with their mouths open and spraying each other and anything nearby with food.