[quote=@Buddha]
Besides, everyone has all five chakra natures, it just takes a lot of skill to use all five (i.e. to the point where someone that uses all five is revered as God Shinobi.. point in case, Hiruzen.)
[/quote]

Eh, that came down to Hiruzen's skill and strength. Hashirama had the same title, and he only used his wood techs. (well, most notably, anyway.)

Hiruzen mastered all the elements, unlike Kakashi, and I suppose that's where the title really lies.