Scheduled rides are a neat strategy, but they're tough for consumers to use effectively. For one thing, if you're attempting to schedule a last mile ride after you get off the subway, your arrival at the pickup point could be subject to minor delays. But on the network side, a few minutes on each ride impacts efficiency in a major way.
Personally, my biggest (non ethical) issue with Uber/Lyft et al. is that they're unreliable. There are common rides you can request (e.g. leaving the urban core after work when drivers want to be heading in for bar service) that drivers simply don't want to do. I don't think there's a faster way to create negative user associations than walking an hour home in a heat wave because the pricing model failed.
Personally, my biggest (non ethical) issue with Uber/Lyft et al. is that they're unreliable. There are common rides you can request (e.g. leaving the urban core after work when drivers want to be heading in for bar service) that drivers simply don't want to do. I don't think there's a faster way to create negative user associations than walking an hour home in a heat wave because the pricing model failed.