Designing for the Everyday Person?

How is it possible to design for everyday life? There are such a variety of people living such different lives that it’s almost impossible to group them into one mass. These people are so different and all have different needs that can occupy a shared space in one day. The community can occupy places that weren’t necessarily designed with that intention, but people like to adapt things and spaces to fit their own needs. What if we left the “in between spaces” up to the user to determine how to use it as they see fit. A public space can be completely empty and deserted one day, but filled with lively people the very next day, and maybe we don’t need to OVERLY design public spaces, so that it can change and adapt with the people and their everyday needs. Of course, as designers we should always take the users into consideration, but when the users are so different and so broad we should leave it up to them.