I feel like we're talking past each other.
You said: dev coin is a good model-- e.g. writer creates something, uses devcoin, 90% goes to them, 10% to devcoin miner.
I don't understand why a writer wouldn't just use dollars-- create something, sell it for dollars, writer keeps 96%, PayPal gets 4% for processing the transaction.
Or Bitcoin: create something, sell it for Bitcoin, writer keeps 99% BitPay gets 1% for processing the transaction (Bitcoin can do this because it is more efficient than PayPal/credit card/traditional fiat, that is where the wealth is created).
Or is there some magical way that using an alt coin creates wealth out of thin air? I don't see it....
On the larger topic of creating wealth, accretion of wealth must be seen beyond the Efficient Markets hypothesis, that rational actors gauge the intrinsic value of a object, commodity, stock based on sound real world information. The standard interpretation is that the Gold has value because I can exchange it, but what is gold backed by? belief that it can be redeemed, no one can eat gold, but it is precious theoretically because people use it for art and technology... yet, somehow the majority of traders, trade based on trends instead of real world data to back up their assumptions.
What happens if we separate the belief, assurance, confidence from the true value of an object? What if we take into consideration how much others will want it, believe in it? Gold for example, if taken on it's pure value, how valuable is Gold truly? We must gauge it according to it's uses in Medicine, Electronics, Aeronautics, Dentistry,etc and exclude it's prestige Industries: Jewelery, Finance, Awards, etc. The value drops dramatically if these sources of demand are excluded from considering it's value, yet people are swayed by it's prestige; So too can an idea, or cause be created by being backed by a coin, and this is not the only reason that coin would gain value.
A coin would gain value by the percentage of the population that are aware of it, by the people who believe in it's purpose, By sheer human generosity, by it's usefulness, the value of it's community, the products that use it, many many reasons, and like all values it would be changing at all times by the priority of all the factors that affect an object and the percentage of actors trading the object actively, plus of course the prestige factor of future gains, speculation.
Bitcoin has solved a lot of things, this is one of them, it is the gateway for all these alt-coins and causes to reach true wealth... Bitcoin links to true wealth directly and the new coins link to it creating a ecosystem of coins.
Now this new paradigm must be viewed as a new operational model and the potential complexity of the system may become apparent: People are creating organizations founded on an idea, a cause, a belief and applying a reward points model around it, in essence we are gamifying the system, people like to be challenged and being able to gauge there success is very appealing to people, Human psychology.
so for example. I create a merge-mined-coin as a general interface for wealth, a portal for hyper-exchangeable items(fiat, gold, silver, etc) and tack a strongly backed cause, executed with clairvoyant precision(really good interface and marketing) with a excellent POW system in place to gauge the causes success or failure; Those who believe in the work that is being created by the people earning the rewards through the causes POW, will with generosity donate to the system with the understanding that their purchase is helping the cause by monetizing it's value, which at a later time can be redeemed back to them. If the cause is successful as more people become aware of it it will accrue value increasing marketing awareness until it reaches equilibrium of awareness and willing actors to participate in it at their own discretion.
It's a charity/NGO with a reverse payment option tagged to it. We are basically turning a Idea/Belief/Cause into a stock to fund actual real world actions.
And this response does not even address the hyper-complexity of a vast ecosystem of coinified causes... it truly is programmable money, coins within coins within coins, stacked on top of each other.