Mixed usage is good for the community and biking if done correctly. The idea is to bring shopping closer to the community rather than centralizing it and placing it in a shopping mall development where everyone must drive to shop. Centralized shopping venues are good for developers and suitable for driving but very space inefficient so far as parking lots are concerned and encourage traffic on the road.
Keeping shopping as local as possible encourages people to walk and bike to do their shopping close by instead of drive. Small shops along a road with housing above or in back are most convenient and efficient for residential shopping even if prices might be a little higher. Residents save by not having to drive. It is convenient and transportation efficient. It is even better if streets with mixed usage are closed to car traffic with only delivery trucks allowed making the streets part of the walking and biking experience.
This is the way it is in many places in other countries. These areas attract many American tourist shoppers, so why not have such places in our city? It would be a little like Santana Row but smaller and without the parking lots or cars located in many neighborhoods spread throughout town. Residents living there could walk out their door and enjoy a coffee or meal next door or walk or bike to shop for groceries or other goods not far away.
Such small one or two block communities would bring everything closer to where residents lived instead of requiring them to drive to shop. This would vastly reduce the number of cars on the street, reduce the hazards cars present to residents, and reduce noise and air pollution. But most of all it would be very convenient to residents. This is the way neighborhoods used to be before cars changed everything. It is environmentally better and more convenient and safer for residents. Most of all it would be most Growth Sustainable.
So why should the city start thinking about a lot of small such mix use communities spread throughout our city rather than encouraging huge centralized shopping areas with huge parking lots and cars driving there that add to traffic jams?