Because it's a very expensive way to move relatively few people? Trains great if you need to move a large number of people between few destinations, less so if

Because it's a very expensive way to move relatively few people? Trains great if you need to move a large number of people between few destinations, less so if you have a smaller number of people or many different destinations. The city next to where I live cancelled their light-rail project, because it's insanely expensive and yields no benefit over busses, in fact busses are more flexible. If your distances are short enough trains again make no sense. You also still need to get people from the stations to where they actually need to go. It's rare that a train station is your end destination. Busses work, but they are a little slow, taxis are faster because they normally go direct.