There's a difference between good repetition and bad repetition. Good repetition should be challenging and be straining you, either due to difficulty or how often, how fast you have to repeat the task - a lot like climbing M+. Bad repetition is the equivalent of getting full 226 for killing one boar a million times.
To use real life examples, if you're used to servicing F-15s or MiG-29s, your skill as an aircraft mechanic only really increases with time spent with a F-35 or Su-57 fighter jet and its maintenance, and no matter how many times you "service" a balsa wood model airplane, or even a F-15 or MiG-29, you'll never be qualified to work without supervision on a modern stealth aircraft. This is the same reason quests used to go green, then go gray for granting experience, and why mobs stopped giving experience to you once you were 10 levels above them.
From everything I'm reading, Crimson Spears wants good repetition, and Glorious Leader wants bad repetition. I can't really be too sure about that second part, what with all the semantics and obstinate refusal to acknowledge the commonly implied and understood definition for the word
in the context of WoW and its community.
Bob: "Yeah man, I'm doing some mad progression in Classic!"
Jim: "Cool! What are you progressing - AQ40 or Naxx? Have you gotten an Atiesh for your raid yet?"
Bob: "No, I'm more into the number of times I've killed Hogger at level 60. Like, the kill count goes up by one every time I kill him! One shot him every time. Wicked, right?"
Jim: "Yeah... I'm GoInG bAcK tO ReTaIl."