I'm glad you said this so succinctly.On the issue of why there are so many more Star Wars books than Star Trek books in bookstores, the explanation is simple. Star Wars is more popular. Way more popular. The other half of the puzzle: Star Trek was at its peak of mass popularity nearly fifteen years ago, and until the Abrams movie, it was declining steadily. What more explanation does anyone need?
Everything else about Star Wars fandom is (demographically) the same as Star Trek fandom, so trying to explain this phenomenon by way of the existence of e-commerce, the availability of online reference sources, editorial choices, sheer output, or anything else mentioned in this thread and elsewhere always seems somewhat disingenuous.