Going out on the street is a necessary step to get to bars, stores, restaurants or any other place with a specific purpose. I can imagine it being incredibly annoying if every time you go out to get some groceries or have a coffee with a friend, random people walk up to you and try to strike up a conversation that you're sure you're not interested in. Even though they mean well most of the time.

There's tons of places where striking up a conversation is more appropriate than on the street, go there. If you can't think of such places, it's probably time to stop hanging around on the street all day.