It's not a problem. More another manufactured nuisance of the kind San Francisco seems to enjoy creating.
New Yorkers have brunch later, brunch boozier and--broadly speaking--brunch with a reservation. San Franciscans (or at least my friends in San Francisco) eat brunch at the crack of dawn at establishments that prefer lines out the door to taking reservations. (They may claim to take "reservations" at the door. Those aren't reservations. They're names on a wait list. Lots of waiting.)
It's a cultural factor loosely related to (a) recent population and affluence increases outstripping a locale's (b) ability to build new businesses in the midst of (c) a greater value placed on exclusivity than time. (It's also present in Brooklyn and parts of Los Angeles.)