I agree to some extent, but at the same time, if you're basically going to write regardless of the fact that nobody is reading or responding, you might as well write your stuff on your own without posting it. Part of the nice thing about quests is when the audience participates, and you get feedback.
Of course, Original quests are pretty garbage for heavy audience participation, unless you've got a
strong brand as an author. One of the few authors I've seen able to pull an original setting out of his ass and get strong participation immediately is my brother- And he's been building a following via fanfiction and such for literally half his life. Usually, it's much easier to build interest- At least
initial interest- by using an established setting.
Just to compare the last two quests I wrote, 'Best Game Ever' (A crossover between HP/The Gamer, both fairly popular on this forum) and oM&M (An original fantasy setting), in the first week of Best Game Ever the thread had hit 20 pages... Meanwhile, M&M was only 4 pages after a week.
I don't believe this leads from a difference in quality or quantity of writing- I doubt I somehow lost skill at writing in the time between, and the updates were only slightly more consistent in the fanfic quest.
So, from this (Admittedly limited) case study, I think it's pretty clear that the most significant factor in popularity- At least initially- Is to abandon your original settings, and write in established ones instead.
The problem is, I want to skip the 15 years of writing fanfic, and go straight to the 'Actually have a decent sized audience' part