how can my "badlands" be made a permanent feature in a magical world?

Question

When the gods created the mortal realms, they constructed them within self-contained material spheres. These spheres protect that worlds reality from the void, the chaotic realm that exists outside of it. Within these spheres, the race of humanity can flourish. These boundaries must exist because reality is anathema to chaos. Forces within the void seek to enter the mortal realms and return them to their original chaotic soup.

These realms have self-repair units that repair various cracks that appear within this sphere, preventing the outside from leaking in. This repair system can be similar to anti-virus software (Norton, windows defender, malwarebytes, etc), where it cleans up any residue or some element that doesn't belong that can corrupt reality. Occasionally, through human foolishness or void shenanigans, a crack becomes large enough for the void's energies to enter a realm and infect the area with its energies. These create the "badlands" of the world, where the laws of reality break down and various evil creatures develop.

Reality will ultimately repair this crack, preventing further energies from leaking through and weakening its hold in reality. It also cleans up whatever residue remaining, further weakening the effects. However, the taint can never completely disappear, and the badlands that have already been infected will continue to breed evil creatures as well as defy laws of reality, such as gravity, energy conservation, etc. Why would this be the case?

Answer 1

Since we're already making the comparison to software algorithms, I'll follow that route.

Antivirus software can only protect against signatures, patterns, and actions that it knows about. It doesn't learn or adapt on the fly - it cannot. Instead, effective antivirus relies on near constant updates to counter new threats as those threats become known and solutions are found (this is why you ALWAYS keep your antivirus up to date).

But even with those updates, there are occasionally viruses that simply get too deep into the software to easily be detected, much less removed. One such virus is called a "rootkit virus". These viruses infect your computer's kernel, which is the process that runs and manages all other processes on your system. If a virus manages to get some control of this process, then it's not difficult for it to make the system's antivirus software either ignore it, turn off, stop updating, and so on. And if you do get such a virus, the safest course of action is usually to just reimage your machine, which unfortunately destroy all of its stored data. Sometimes it is possible to just remove it, but it's also not uncommon for such a virus to tie itself in with essential system code, so that removing it will render the machine's operating system unable to function (basically turning your computer into a fancy brick if the virus is removed).

Similarly, this corruption of reality you describe could corrupt reality at a fundamental "kernel" level, such that the only reliable way to remove it for sure is to simply wipe the slate clean, destroy everything, and start over with a fresh software image. Assuming the gods actually care about the mortals they've created (and considering the lengths to which they've gone to protect them here), that isn't really an option.

It's also possible that the gods' defense algorithms don't update or adapt - although I'd imagine that would be essential to combat something that represents the influence of Chaos itself. Regardless, if the gods are not actively updating these defenses, and if these defenses are not sufficiently adaptive and polymorphic themselves, then it is inevitable that Chaos will eventually create a bug that these systems either cannot detect or cannot combat.

Of course, the gods could be churning out updates for these defense systems, and it's feasible that one of these updates would eventually find a way to actually remove this corruption... but if we're continuing with the software analogy, and if that corruption managed to get deep enough in corrupting reality, then you run the risk of "bricking" that part of the world, much like removing a root kit virus runs the risk of bricking your computer by also removing essential code.

Answer 2

The original fragment of energy would have to be expelled for it to be completely cleared up.

Unfortunately, the only way would be to expel it back into the void. Cracking a gate to the void to enable this is (likely or certainly) admitting more trouble than can be expelled. Consequently it is simpler to just keep fixing the damage.

It's also possible that the gods regard completely curing the consequences of human action tantamount to denying humans freedom, because freedom requires real choice and therefore consequences.