But initials being no shorter than what they're 'abbreviating' is no impediment to their adoption - 'www' is 3 times longer than 'world wide web' (in terms of syllables). In fact, I worked with someone who said /wəwəwə/, but this never caught on. [This example is a bit of a cheat, as - regardless of syllable-count - the letters literally [ahem] must be spelled out. Still, I feel the shortness of an abbreviation isn't all-important - there's often (for example) a social aspect to using a code.]