Transit history

Does anyone know the history of SD and why it has developed with poor pedestrian friendly options? the trolley is something but its lacking, the freeways like the 5 and the 163 kinda just cut up the city's available walking/living walking space. i just dont rly understand why this has been allowed to happen. cities like NY have developed in a way that allows for non one person car mobility. yes i understand cities like that are much denser, but why can SD not provide its people with more relaible options other than cars and safe measures for the people on foot or biking?