so based on this theory, languages evolved from the different provinces into the different dialects, which happened to be similar to each other but unfortunately pronounced differently ?
let's put it into a very practical logic... books, that record most of chinese literature and history, are writen, in, mandarin. even hk serious writers (the non tabliod ones) are writing serious literature in mandarin. i think HK's most well known writer, jing yong (not sure what his english name is), writes his books in standard mandarin. of cos the directors and movie companies can choose to film them in cantonese..
i look around me and half the people around me are recruited because they can speak some language we need them to. japanese, korean, mandarin, etc. of cos the core knowledge is needed, but if i were to choose between two guys that know our business decently well, i'd still pick the one that can speak one more language. especially when u do sales, try get a guy that can speak no mandarin but knows product well to do sales in china....