Why Singaporeans must go holidays overseas at least once or more a year?

Soon, it will be end of the year School holidays period again. I am starting to receive brochures, flyers etc touting overseas holidays tours. I then remembered a foreigner friend ever asking me: "Why Singaporeans must go holidays overseas at least once or more a year?", "Is there no place in Singapore worth spending your free time in for a few days?" I was basically dumb-founded and I have no answer to this question.