Well it was a time when the US produced some of its most celebrated coinage, the Saints, Walker Halves, Standing Liberty Quarters, Mercury Dimes etc.
It was also somewhat of a 'Golden' period in US history, the Roaring '20s... soon to be shattered by the 1929 Wall Street crash and the Great Depression of the 1930s.
Another reason was because the 1910s was a more expensive era to focus upon.