Japan could do it easier then China
Japan has one language with multiple scripts. Mainly Kanji, Hirigana, Katakana, and Romaji, all used together in any given modern magazine. Then variants such as hentaigana, furigana, and kanbu, not to mention 3 variants of Romaji. Let's not even get into the order of characters, tategaki (top to bottom, right to left) vs yokogaki (left to right, top to bottom). There have been many attempts at reform, including one suggestion that the Japanese just speak French and all problems solved. To learn more:
http://en.wikipedia.org/wiki/Japanese_script_reform
On the other hand, China has the opposite situation, two main languages (Cantonese and Mandarin) sharing one writing system that is mutually intelligible. I recall going to a Chinese restaurant with my boss, who was of Cantonese origin, who could not communicate with the waitress who spoke Mandarin. Not a problem, the waitress handed my boss a notepad and pencil and she wrote the order, which was understood by the waitress. Seems to me if the Chinese adopted an alphabetic system this would impede communication between the two language groups.