Can't really speak for others here, but if I had the choice of running a challenging non-linear dungeon with reasonably difficult mechanics and mob placement three times a week to cap tomes vs faceroll 20-minute experts six times a week, I'd do it. But if I had to still run it six times a week like expert I'd never touch it.

Better yet, give me a totally brutalizing system like Wow's Mythic+ which is basically as hard as the hardest raid tier in the game except condensed down to five people instead of twenty, with ilevel gear rewards that match the challenge, and I'd be even happier.