Why the Chinese language should not adopt phonetic writing?

This is part of a comment posted to Xujun Eberline's blog Will Chinese Go Alphabetic? Re-posted here as a standalone piece. "Phonetic" and "alphabetic" are used interchangeably when referring to a writing system.

There's an often-forgotten aspect of the resistance against Chinese romanization: unification of China. A number of scholars have expounded this idea since about one hundred years ago. The earliest I read is from Sun Yat-sen in his "Three Principles of the People". If China were to use an alphabetic writing system, people in different regions of China would soon find it impossible to communicate with each other due to great differences in pronunciation of the dialects, and China would disintegrate into many small countries as Europe. Sun's voice might appear weak against the few prominent figures in the 1920's and 1930's advocating romanization, because Sun's major concern was something bigger. In fact, that idea is largely unknown to most people, in spite of reiteration by a few scholars mostly in Taiwan. Generally, in the past 100 years, when the Chinese woke up to the fact that China is weak in power, romanization of the Chinese writing system would gain momentum, and subside in other times. I think the latest wave was in the 1980's, on a much smaller scale than its predecessors. With economic boom in recent decades, romanization is only a wishful thinking of the foreign students interested in something about China except the language itself.

To be fair, I think it's proven that children spend more time studying Chinese to a literacy level than studying an alphabetic language. But in view of the benefit of national unity, and to a lesser extent, artistic and literary beauty, let the kids, or foreign students, suffer! (By the way, I'm not sure if there's proof that simplified Chinese takes less time to learn than the non-simplified, but all anecdotal evidence suggests so.)