When it comes to the majority of casual readers (the types giving the 1 star reviews saying a game is too short) the total wordcount number isn’t all that useful. Single-playthrough length is far more relevant. Many casual readers will determine the value of a story after just one playthrough. It’s just a reality.
I think the casual audience drives the evolution of a medium more than the hardcore does. The casual audience has long since left parser-based IF (exits are NORTH, WEST and SOUTH), for example, but there of course remains a solid fanbase around it. I think the stats-heavy, lots of branches, high replayability, “game”-y choicegames will go the same way. There will always be a fanbase for them, but casuals will move elsewhere (they always do).
My guess is that the casual audience sees pages full of text and expects a story experience first and foremost, one with as much narrative depth as you’ll find in any ebook. Something that takes more than one sitting to go through. This will lead to a rise of “interactive novels” as opposed to “interactive games”. Stats-lite, with branches geared towards customizing a set story instead of branching out into multiple ones.
Maybe I’m wrong, but that’s what the numbers and reviews seem to indicate to me. Making any reads into the ‘casual audience’ is always very hard to do, because they by definition aren’t here posting on the forums. Regardless of how the future goes, if you write it–they will come!