They should be. Just a matter of someone stepping up to write that section. The modern theory on market makers has existed for less than a decade and only matured in the last few years, so it just hasn't had time to percolate out. Even here on Less Wrong, where prediction markets are very salient and Hanson is well known, there isn't a good explanation of the state of the art. I have a sequence in the works on prediction markets, scoring rules, and mechanism design in an attempt to correct that.