It is too bad, however, that apart from the West Dublin/Pleasanton Station, BART has no infill stations planned. Nor is it alone on this matter: Cities with extensive commuter rail and subway networks in the United States, including New York, Chicago, and Philadelphia, have been more interested on extending their lines out into the suburbs than filling them in. One notable exception is Boston, where four new stations are planned to be added to the Fairmount line to add to the transit options for people living in underserved neighborhoods south of downtown.
Stations on all of our rail lines are quite close together. If anything I'd say there are too many stations. I think localities should change their zoning laws to allow for more infill development around those stations, but we don't actually have a shortage of stations.