You have not made any arguments. As minmay was trying to say (I think), the invocations skill is defined exclusively as a mechanical device - it has no other features in the game, so how can it be "inconsistent" vis-a-vis flavor? Why would being "crude" imply that they should have subnormal invocations aptitude? You're bringing preconceptions about certain tropes (e.g. that eloquence or sophistication makes it easier to use divine abilities) into the game and implying that those preconceptions being misaligned with the way the game is structured is an "inconsistency" in flavor.
Then you come in here, use this misinformed and singular argument to say "the devs have completely lost touch with what coherent flavor is," then, instead of refuting counterarguments, throw up your hands, insult the forum and the (mostly polite) people who have responded to you, and say "I'm too good to discuss this any further."
go away
Edit: Also, here's the manual file on Hill Orcs:
Hill Orcs are Orcs from the upper world who, jealous of the riches which their cousins the Cave Orcs possess below the ground, descend in search of plunder and adventure.
Hill Orcs are as robust as the Mountain Dwarves, but have very low reserves of magical energy. Their forte is brute-force fighting, and they are skilled at using most hand weapons (with the exception of short blades, at which they are only fair), although they are not particularly good at using missile weapons. They prefer to use their own weapons. Orcs are poor at using most types of magic, with the exception of conjurations, necromancy, and the elemental magic of earth, fire and ice. They advance in levels as quickly as Humans.
What about this implies that they are "crude" or impious?
Also, hill orcs don't worship Beogh exclusively. Is Zin "the god" of Draconians or Tengu because DrPr and TePr start with him? No, he's just one option. I mean, hell, more DD worship Makhleb than HO worship Beogh probably