What is the lamest prestige class concept (to you)

[Rubik]

That's the thing though. Its not "Willing only" or "Harmless". It has a Will Save, which means that to resist it, one must overcome a minimum​ DC of 23. Minimum. Not likely on most lower level characters, and by the time that someone is casting this even the devs were aware that the DC was likely to be higher. Also, BOOK OF VILE DARKNESS!

And?

Just because it can be used offensively doesn't mean it has to be. There's nothing about the spell that makes it inherently Evil; otherwise, we couldn't come up with useful, non-Evil ways of using it. And in this case, doing so is very, very easy. So easy, in fact, that the idea of it having the [Evil] tag (even apart from it not using Evil energy) is actually kinda stupid. Kind of like Deathwatch having the [Evil] tag. There's nothing actually Evil about it.

Like I said, I got nothing on Arcane Archer. Did you miss my point though, about how the only thing that can be assumed to be in use when writing these books is Core+The Book itself? In core, which is where DD comes from(and for the purpose of this exercise, Core Races is referring to only the PHB ones, not any MM ones) the only race that has anything to do that meshes with Dwarven Defender's shtick about not moving is the Dwarf. In Core+Races of Stone, the Shadowcraft Mage is gnome-only because, from the text as written, Gnomes are innately magical in a way that no other race in those two books are. They can work illusion magic in a way that no other race can, thus the ScM is gnome-only.

And yet a human/elven/dwarven/halfling illusionist is just as capable of taking and using shadowcraft mage as a gnome is, apart from the misplaced and useless racial prereq.

Thematically, nothing in RKV references anything that might be inferred as a racial stereotype.

Which is why it (rightly) doesn't have a racial prereq. And neither should any of the ones I mentioned above.

Give me a class not listed above that has a racial limitation and I can likely see the reason intended by the devs. Apparently that is rare here. For all the talk of RAW this and RAW that, apparently you guys have lost sight of the fact that the devs have not only RAW to work with, but FAW to work with as well.

"Intention" doesn't mean "good thing." A lot of intended ideas are really, really bad and serve no useful purpose.

Look at Reality TV, for instance.