Japanese people, drink in and sleep on the street. Why?

What makes this phenomenon so popular? And the reason why until now, local authorities and police have to shake their heads helplessly before the phenomenon of "Rojo-ne"?

In Japan, the phenomenon of "Rojo-ne" (called sleeping on the street) is no longer too strange for the people of Japan, even this is an obsession of many people. In particular, this phenomenon is common in Okinawa Prefecture. Both men and women lie down in the middle of the road to sleep, they ignore the passing traffic, despite the danger that occurs.