The Skaldskaparmal is not a collection of stories for their own sake. It is a handbook for poets, and Snorri tells the story of the mead in order to explain a working vocabulary. Skaldic verse names things by periphrasis, and the accepted periphrases for poetry are almost all drawn from this myth: poetry is Kvasir's blood, the dwarfs' drink, the liquid of the vats, Odin's find, Odin's drink, the gift of Odin, the drink of the Aesir. A listener who did not know the story could not follow the verse.
That gives the myth an unusually practical function. Other sacred substances explain a rite; this one explains a craft, and it explains it in a way that makes every competent poem a demonstration of the claim. To compose skaldic verse at all is to use the mead vocabulary, so the poet is continually asserting that what he is doing is the distribution of a stolen divine liquid.
The valuation that follows is worth noticing. Poetic ability is not a gift of temperament or the result of training in this account. It is a substance that was made by murder, acquired by murder, held by a giant, stolen by seduction and deception, and vomited into cups. Nothing about the chain is dignified, and Snorri does not present it as though it were. The one moral distinction the myth draws is between good poets and bad ones, and it is a matter of which portion you got.
Odin's part in it is characteristic. He obtains the most valuable thing in the world by lying about his name, murdering nine workmen indirectly, seducing his enemy's daughter and breaking his word to her, which is the same method he uses for the runes and for wisdom generally.