Its not nitpicking, at all, it's a very good question.
Unfortunately, I doubt you'll acquire a definitive answer to this, as the nature of the show priveleges the denial of a neat narrative, and the mystery you pose is just one thread in a carpet of loose ends that purposely don't get tied up.
I think one of the fundamental components of True Detective is the notion that there are no happy endings, and it is for this reason the show is so closely compared to film noir. The truth remains out there, but simply unobtainable (by either the protagonists, or us as spectators). Denial of conclusion is an established technique within Noir, at least: look no further than Chinatown for good examples.
Whilst its unlikely we'll be able to form an answer you'd be able to mark as correct, a little deduction lets us reasomanly speculate as to why no more murders were exhibited so publicly. I hope others will contribute their theories and observations, and we might collaberatively move towards a 'most likely' scenario.
For me, the key to this lies hidden in your question: The fact that the year of Hurricane Andrew is described as a 'good year' is revealing, when attempting to discover the significance of it.
Conventional Wisdom often declares that in a crisis, humanity will automatically band together in support of mutual security. [Stories from Hurricane Katrina](, however, flew in the face of this misnomer, revealing tales of people taking advantage of chaotic circumstances to mask their own deviant behavior, and getting up to some pretty dark shit.
From the BBC:
"There is rapes going on here. Women cannot go to the bathroom without men. They are raping them and slitting their throats," she told Reuters. [...] Death was everywhere, both inside and outside the Superdome [...] "They killed a man here last night," Steve Banka, 28, told the Reuters news agency before he left on Sunday. "A young lady was being raped and stabbed. And the sounds of her screaming got to this man and so he ran out into the street to get help from troops, to try to flag down a passing truck of them. He jumped up on the truck's windscreen and they shot him dead," Mr Banka said.
It is no co-incidence that a hurricane features so prominently in the series, and the behavior of Childress (and those who made themselves accesories to his ritualised murders) foreshadows the 'darkness' within humanity that was exhibited during Katrina. Its a brand of depravity that fits perfectly into Cohle s nihilistic pontifications on the latent evil within mankind.
The reason Hurricane Andrew was a 'good year' was because of the total lack of accountability it created. Childress, who is a sociopathic (but NOT stupid) man understood that, much like Katrina, he could excorcise his barbarity without consequence by taking advantage of the disorder. Anyone that went missing during this period would be most likely comsidered lost to the disaster.
It was a good year because Childress didn't have to be as careful, which would infer that the rest of the time he was careful.
Now Dora Lange and the Lake Charles victim were murdered ritualistically, but at a seperation of over 15 years. Whilst the link will inevitably be made, the low frequency of these discovered corpses makes the task of finding the culprit incredibly unlikely. Couple this with the fact that Tuttle was interfering/supressing the investigation on account of his involvement, it's understandable to believe how the cult (comprised of powerful and influentual men, if Tuttle is anything to go by) would believe they possess the neccesary influence to bury a murder investigation every decade or so.
Whilst murder is perhaps the most serious of crimes, managing the aspects of its investigation so as to limit the force of response is an aspect of the very thrill the cult is pursuing in the first place. These are people that obtain arousal at the extension and execution of their own power. By comitting such a barbaric act, in such a sinister way, making it public and getting away with it is the very point of the excorcise.
The bodies were found because they were supposed to be found. The others that Childress killed were for his own pleasure.
Childress didn't want to be caught, but the cult (which used him as a tool) could facilitate a 'smothering' of the ritualistic murders, but obviously not all the murders Childress commits. It is for this reason that the only bodies that are found are the ones that are meant to be found.