I don't think it is very nice to make the assumption that a high density of social housing will result in a ghetto. Do you have sources that people in social housing are more prone to violence and crime?
It's neither an assumption nor about being nice. As mentioned isolated dense social housing has been observed to create conditions that alternate plans can counter. It also doesn't have to be about violence or crime--mere the neglect of neighbourhoods that are not 'in mind' of decision makers for simple things like maintenance of roads, lights, etc all contribute to this.
Ghetto doesn't imply violence or crime to me. Per Wikipedia:
"A ghetto is a part of a city in which members of a minority group live, typically as a result of social, legal, or economic pressure."