This article has good parallels with the NYT reporters who feigned being asylum seekers to travel to Australia by boat and document the horrible treatment experienced at all stages by those who take this journey [1]. I could easily imagine you arguing that these NYT reporters were terrible because they could have been on board a boat that sank and caused search and rescue people to go out and waste their time trying to find them. Equally, I could imagine you arguing that they denied a few genuine asylum seekers the room on a boat and therefore they're still stuck in a dangerous situation. However, that's completely missing the point.
The point is that without people undertaking these experiences and documenting them, the harsh reality of the situation is never quite realised. You don't end up humanising the debate around how these situations are handled, so people show less empathy towards the situation. This is a terrible situation to be in, because we then forget that we're dealing with actual human beings and not just nameless, inert objects.
In the case of the judicial system, it's one thing to know that the system mistreats and punishes people but it's another thing to actually hear the stories about the diabetic being denied proper medical treatment because of some power-tripping guard. That's why you had to go out of your way to clarify that you weren't justifying their ill treatment of him - it was humanised and put into real-world context.
In the case of the asylum seeker report, it's pretty widely known that they experience harrowing conditions and receive pretty repulsive treatment by the various governments in an effort to deter their coming to Australia. But without actually hearing the stories of the hopeful children excited about the journey as they kill time in a refugee safehouse playing in the pool with literal spare parts of broken equipment as toys, or the blind hope of the guy wanting to make a better future for his kids whilst simultaneously denying to himself that he won't just be chucked in a jail on a third world island, you don't experience the same empathy for their situation.
It's a direct counter to the rhetoric used to de-humanise the whole situation. In the case of asylum seekers, they go from being 'asylum seekers' to 'boat people' because the thought of turning away people fleeing some war-torn hellhole to find a better life is harder than turning away a few people who decide one day to hop on a boat to 'jump the queue'. The re-humanising of the whole argument through actual stories and events is the strongest way to put some emphathy back in to the argument and highlight that we are in fact dealing with other human beings, capable of thinking for themselves and having their own families and loved ones.
In the case of the judicial system, it's that these people are criminals who exist in some isolated void without family or former childhoods or any of that and simply must be dealt with so that they can't commit another crime, rather than humans with a story and a life larger than the crime they allegedly committed. Hell, the author himself said that when he was practicing, he always assumed he was trying actual guilty criminals and that once they'd been dealt with, it was all over. It was only afterwards that he started wondering about the broader implications of what he was doing.
So because of that, I completely reject your statement that it's a waste of resources and time to undertake these sorts of investigations. Does it divert theoretical resources away from the ideal task that those resources would be addressing? Sure. But it's an extremely valuable use of those resources to highlight the broader issues at play and put some human empathy, so often sorely missing, back in to the debate.
[1]: http://www.nytimes.com/2013/11/17/magazine/the-impossible-re...