Isn't the problem in the fact that Zuma and his cronies brought a lot of Zulu votes into ANC, thus crippling Inkatha party (violence between the two far outslaughtered the evil apartheid government), so they had to indulge his faction.
It's basically private security and armed citizens defending their neighbourhoods, cops don't do much, some even joining the looting. It's but a more extreme version of daily happenings there.