Simulations, games in general, and analytic history, are non-linear. That is, you can wander all over the place and still be somewhere. Flip through a book, and you pick up pieces out of context. Make different moves in a game, and you have a context, because the game allow, even encourages, deviating from the historical events. Linear media can be a drag at times, non-linear media keeps you on your toes.
Analytic history is written with non-linear use in mind.
You can wander around a piece of analytic history and still get a lot of useful information. And Now, The Bad News Simulations and to a lesser extent analytic history, require a fair bit of effort on the part of the user. Film is more popular than print because film requires less effort to get something out of it. Print is more popular than simulations for the same reason. You don't have to be terribly observant in a bookstore to see which history books sell best.