>It'd be very difficult--impossible at some points--to read and write materials from other "dialects". However, with a logographic approach, everyone can understand that the character 工 means "work" even if I pronounce it like [wirk] and someone else pronounces it like [wak], for example.

I'd like to point out this isn't unique to CJK (Chinese/Japanese/Korean). Languages descending from or based on Latin can be understood, at least very generally, by each other because the equivalent words in each language usually have similar spellings or appearances.