Amazing sig, done by mighty Lokann
What?! No, no and no. The closest ting the Orcs ever had to a "religious" Leader wad Ner'zhul. Gul'dan did not commands such respect, nor did he have such a title. He was the Leader of the warlocks, a small sect of Orcs, who were feared, hated and looked Down upon by all other Orcs. Bad analogy is bad.
Amazing sig, done by mighty Lokann
As I said in my post, Gul'dan is a hero of the Horde that has much potential despite being dead. The Lord of the Warlocks, the Master of the Necromancers, the leader of the Stormreaver clan and the Grand Master of the Inner Circle of the Shadow Council...
As his skull appears again and the runes he painted at Suramar are disclosed by Drak'Thul, a reborn Shadow Council at the service of the Horde could bring him from the underworld, back to Azeroth ...
Knowing that in his last moments of life he redeemed himself and realized how he had been used by the Burning Legion and how the Horde had been used to fulfill the purpose of Sargeras, not surprisingly, Gul'dan is willing to avenge of Burning Legion, and compensate the Horde providing all his occult knowledge ...
Yup. Spelled out right in Rise of the Horde:
"Behold my lieutenant, Mannoroth. Well has he served me and well shall he continue to serve. On other worlds, they call him the Destructor. But here, he is the savior. Gul'dan," purred Kil’jaeden, and suddenly Gul'dan felt weak and sick again. "You know what I am offering your people."
Gul'dan swallowed hard. He did not dare glance at Ner'zhul, whose gaze he felt boring into his back.
Yes, he knew well what Kil’jaeden was offering. Power beyond imagining . . . and slavery for eternity. Kil’jaeden had offered the former to Ner'zhul in exchange for the latter, and Ner'zhul, the coward, had balked. He had not wanted to doom his people. Gul'dan was untroubled by such scruples. All he could think of was the reward Kil’jaeden had promised. "I do know. Great One," Gul'dan said, surprised by the strength and steadiness of his voice, "I know, and I accept my lord's most generous offer."
Gul'dan died before the burning legion was even conceived to be what they became with Wc3.
The reason is as simple as that: The lore was young and if blizz were to rewrite it to fit actual lore it would be completely different.
Back then he was the most powerful warlock because there wasn't another warlock - he was the first orc and humans couldn't use warlock magic. Kil Jaeden and Sargeras were some random demon lords created to make drama out of medivh's story and allow a human to do something evil (there are no evil humans as long as no bad power posses them D: ) like summon some green monsters to azeroth. To make it more interesting the monsters were given a bit wisdom, sense and other good qualities to make them reasonable in the campaign. Old lore wasn't meant to be a lotr-world with some backstage and what not it was created to fit the RTS-game. Topics like this one exist because people seem to overestimate the lore and how it was made.