To add to your point, even if you were willing to invest in a proper network it will take years to get going. People are set in their ways and so they won't stop driving, even the hard core supporters of the idea will drive everywhere for a while. Eventually something will cause them to try transport, but the first time they will fail to figure out how to ride and so be late to their... Eventually they will figure it out and over 10 years you can get a good ridership for the population density. Then over the next 30 years you can get density to increase to the point where there is enough population density to justify the network you needed to create to get there.