Because buses are shared and follow a fixed-route and can't support an on-demand model. It may take a bus over an hour to complete the entire route. Would you

Because buses are shared and follow a fixed-route and can't support an on-demand model. It may take a bus over an hour to complete the entire route. Would you rather have to call for a bus that might take an hour (or might take 2 minutes) to get to your stop when you call it, or would you like to know that it comes at 4:45, 5:45 and 6:45 so you can plan ahead to know when to get to your stop. (failing to run on schedule is a separate issue, but on-demand rides won't solve that). In cities, one solution to that problem is to run at such frequent headways that a late bus doesn't matter -- when I lived in SF, I had 2 busy bus routes that could take me to work, during peak hours a bus ran every 6 minutes, so even if they weren't on schedule I didn't care since I knew another would be along soon. If you want me to ride the bus to work every morning and home every evening, you still have to have buses in mid-day so I can go home early if I need to. Even if those buses are mostly empty.