How can I make this any simpler? Forsaken don't have shamans because they're primarily human and elves, who have no experience with being shamans. It has nothing to do with them being undead. If you replace humans with trolls and make an undead troll faction, undead shamans are an absolute certainty. You have this completely wrong understanding of how the elements function, they're not a benevolent force that despises undeath, they're just a bunch of powerful dicks who lend their powers to whomever they see fit, they're the former minions of the Old Gods. Goblin shamans bribe the elementals to use their powers for god's sake. This is the last time I'm gonna point this out.
I have a feeling you don't quite grasp the size of Lordaeron or the fact Arthas' Scourge forces were entirely concentrated on the northern Eastern Kingdoms, which is about 70% Lordaeron. This is why the overwhelming majority of Forsaken are humans and elves, because that's what Arthas killed the most. Are there members of other races among the Forsaken? Obviously. Does that somehow mean that the Forsaken "aren't that closely tied to Lordaeron"? Absolute tosh.
Also, Draenor orc shamans weren't denied by the elements because they practiced dark magic, they were denied because they were tricked into killing draenei by Kil'jaeden. Draenei had shaman of their own, which is why the elements didn't want to help in slaughtering their own servants. It is after the orc shamans got denied that they rerolled warlocks.
Oh, so dark shaman are not shaman? Why are they called dark shaman then? Wowwiki really isn't doing you any favors, mate.
How am I supposed to give you facts when you consider your personal opinion a fact and any actual facts that don't coincide with it are suddenly my personal opinion? Here are some actual facts for you:
1. There's no reason an undead can't use the power of the elements, unlike the Light, most elements don't care.
2. Forsaken are primarily Lordaeron humans.
3. An entire race can force the elements to lend them power, an entire race can also bribe the elements to lend them power.
4. "Dark shaman" are shaman.
All of these are facts that you don't consider facts for whatever reason and since I can't really seem to convince you of this, condescending mockery is the only thing keeping me interested in this conversation. You better appreciate.