If I'm not mistaken, the simplified script was introduced by the Communist Party under Mao to improve literacy in mainland China. Hong Kong, Macau and Taiwan were unaffected and continued to use the traditional script. The simplified script wasn't opened up to overseas Chinese communities until many years later.
Today, Singapore and Malaysia teach exclusively using the simplified script (apart from calligraphy classes, because traditional characters look MUCH nicer when displayed) Hong Kong, Taiwan and Macau are still actively using traditional. Could it be a political reason? Maybe, but I can't say for sure.