I think it is kind of silly. Virtually everyone's apartment or house has room for a bicycle, even in San Francisco, so these lockers serve no significant need. At the same time, they cost public money and essentially award a few people exclusive rights to a parking space.
Granted, sometimes you'll have an older apartment building with a tiny elevator and narrow stairs going up five or six floors, so getting a standard bicycle to an apartment on the top floor is hard. That's why they make folding bikes - and apartment-size refrigerators, 24" ranges, stackable washer/dryers, and the other things you have to put up with to live in the city. Even those older buildings usually have a common space that could be converted to communal hanging bike storage.