There is perhaps a much broader range of evergreen grasses or grass-like plants available for the warmer climates of the South and West Coast than there are in colder areas of the country - perhaps that is why you observed less of the deciduous grasses like Miscanthus. And too, these are warm season grasses, so are not readily apparent this early in the season, often being cut back in winter. FWIW, I sell a good number of Miscanthus, as well as Panicums, Calamagrostis, Molinea and other deciduous grasses, but sales of my evergreen grasses outpace them by perhaps two to one :-)

Coastal southern California has such a long growing season and such a mild climate that bloom times for grasses often start very early in the year and extend well into the fall.