There is large spectrum from we redistribute everything to we redistribute nothing. We can probably all agree that "justice" doesn't exist at either extreme, but it is also a vague term and its exact location on that spectrum will vary based on personal opinion. That said, a lot of people believe the location of "justice" on that spectrum is closer to the "we redistribute everything" side than where we currently sit and a move to more redistribution would therefore yield more justice. That is the opinion put forward in the article and hence the headline.