I imagine numerous cities have been spending countless millions on studies and consultants to figure out an answer to that one. Personally, it's the lifestyle

I imagine numerous cities have been spending countless millions on studies and consultants to figure out an answer to that one. Personally, it's the lifestyle they choose. They make little micro houses out of rubbish and tarps equipped with couches and mattresses. They make comical signs such as "need money for booze" for laughs and get free food from charities or shelters. There are some that have no where else to go but a non-trivial number are there because it's cool these days to live a nomad hipster life. Downtown Austin is/was somewhat of a party area with numerous bars and clubs and it gets so popular on weekends that the police shut down some of the streets for pedestrians only. It was a festive place to hang out -- which is part of the attraction. In most cities areas that get taken over by the homeless become blighted places regular people never venture to (i.e. skid row in LA). The reason that people are so freaked out in Austin is that downtown is full of residential and commercially office buildings which results in people having to walk through these areas trying to get to/from work.