Evicting many for the crimes of a few

More on the evictions of hundreds of families from a building in Johannesburg:

Police break down doors in massive crackdown


Foul hellhole is what hundreds called home

Important portions from the first article:
Portia Mashilo, who stood outside the building with her newborn baby, complained about the way the police had rudely woken her up. "This reminds me of apartheid, when the police just used to force their way into our homes. Now, even in democracy, they are doing the same thing. It is not right," Mashilo said.

But [police inspector] Naidoo said police had been compelled to act against "bad buildings" because intelligence showed that Hillbrow was the nerve centre for most crimes committed in and around Johannesburg. "We have more than 30 different nationalities living in Hillbrow and there is a major market for stolen goods, because many of these people cannot buy anything on hire purchase," Naidoo said.

"Most of the crimes committed are done out of buildings like this, and that is why we are coming down hard on such places."

My questions:
why are the police simply evicting people without rehousing them?
why isn't the South African government doing enough about the housing crisis?
why arrest the illegal immigrants (it's not at all clear that they're all criminals)?
why evict the many for the crimes of the few?