It's coded. You see "handout" named as such more often when it's low-quality, inefficient service. With a system like BART, the whole thing was motivated by pressure to relieve middle-class downtown commuters specifically, and everyone else by chance(hence a design without redundancy that requires a midnight service shutdown). Geometry forces it to pass through many types of communities, but during construction, the slightly richer, whiter communities had more room to shape their relationship to the system:

Prime examples of how public pressures escalated the cost of the system are the Berkeley subway and the Ashby Station. After originally approving a combination aerial and subway line through Berkeley, that city later came to oppose the plan in favor of a subway-only line, which was much more expensive. The new plan necessitated redesign of the Ashby Station from an aerial to a subway facility. Extensive controversy and hearings ensued for the next 2 1/2 years, finally to be resolved by Berkeley residents voting to tax themselves additionally to finance the changes they wanted. Next, a Berkeley City Councilman filed a successful suit to redesign the Ashby Station, yet a second time, asserting the use of skylights in the original plans was not a true subway design. [0]

And indeed, the "nicer" stops on BART tend to be underground, while the "inexpensive" ones are mostly aerial alignments adjacent to freeways. (See the history around "freeway revolts" and you get a similar picture of class/race division.)

[0] http://www.bart.gov/about/history/history2