There isn't a demand for a million musicians, a million basketball players, or a million writers. There's a demand for millions of shelf stockers, but there's 10's of millions of people who are capable of doing the job.
I wonder how much of that is true. It seems to me that there is plenty of demand -but- getting exposure is another story. It's similar to writing apps. Tons of developers write apps but only a few make it big. Some of that, of course, is due to those apps being really good. But it's also because large companies can get their brand out there and sell it. Notice how the app stores feature big brands like Disney. A better solution to music and almost every other industry would be adjusting the business environment to promote discoverability by "buyers". Social media helps with this, but we need more creative ways to find good new music, books, apps, etc.
This is mainly due to the fact that there is no "stable" Wikipedia -- things change so quickly that citing Wikipedia makes it very difficult for anyone to actually look up whatever you were citing. If there were "snapshots" that were widely distributed, say at the end of each year, one could simply cite those snapshots.
There is actually, an effort to change some of this. The Encyclopedia of Life (eol.org), which imports Wikipedia articles about species, has a process underway where curators will be able to edit a Wikipedia article, mark it as "curated", and then have that expertly reviewed article available for reference. Think of it sort of as an EOL branded version of the article, lending more weight to its accuracy. The main article can still continue to be edited and changed.
Thus spake the master programmer: "Time for you to leave." -- Geoffrey James, "The Tao of Programming"