I thought it was an interesting observation, though I don't necessarily agree with it. It made me think of the advice Christopher Vogler gives in his book about not thinking of the Monomyth as a step by step guide (if I remember correctly). Advice which I didn't really 'get' as much as I thought, until I saw the results of going against it for myself in my own tinkering with this structure as a gaming aid.
Anyway, much of my thoughts are in my reply to the fellow member, in the rest of this post. I hope these help.
I've been tinkering with use of the Monomyth in solo gaming since April of 2011now (dang! Can't believe I'm still tinkering since I posted thishttp://games.groups.yahoo.com/group/Mythic_Role_Playing/message/4816).
I've come to look at these structures as a sort of wire frame on which to hang your content, or alternatively, as a map you consult when your game seems to be going nowhere or you feel unsatisfied with it. This is something that the author of the book I've been using as a reference said early in his work, but it took me experimentation to see what he meant.
It's true that they are going to put some constraints in the flow, but those are there to ostensibly help you towards achieving a certain type of "story", if that is what you're looking for. Within those limits, though, there is stil lroom for variation.
Incidentally, I think that a mix of both approaches is necessary for a more satisfying game. In the Monomyth, I think each stage demands a different consistency to the mix. Some may require a more explicit approach (like, "here I am in the Ordinary World, and I want to establish certain things before the adventure gets going"). Others will need more of the "map sitting in the background" soft touch; I'm still trying to work those out for myself.
For example, in my last proof of concept solo session, I found myself at odds with the need to have my PC spring into action. He's a computer crimes law enforcement member, and he both witnessed an attempted murder on the street and later found his place was being bugged. The attempted murder is not his jurisdiction, so he's only a witness. Being bugged: that he really has no reason to investigate on his own either (since he can just report it to his own dept chief and get assistance, or so my logic goes-- and maybe that's the answer to move forward), so I was sort of stuck.
I ended up taking some time off from the game (been playing a lot of Virtua Fighter), and then realized that the answer was there in the Monomyth structure that I want to use: the stakes for the Hero are just not high enough. His Ordinary World hasn't really been turned upside down. On my next try, I know I need to use Mythic (or a randomizer) to raise the stakes in a manner that really gives him no choice but to take action (say, maybe someone doctors the evidence and he ends up accused of the murder, or he finds evidence that his police dept is involved-- just finished reading Serpico, lol).
Anyway, I think that the 9Q's can also be used in this way if you don't like feeling constrained. Just use them as a reference for when your game feels lame,or stuck somewhere.