That may describe your patterns but it doesn't match my lived experience with a game on Steam... I added a demo and saw sales decline. I removed the demo and saw sales increase. I've heard similar stories from others.
Besides, even if it was, it's not like developers set out to make a non-compelling game. Like woops, let me just press the "compelling" button before shipping!
Unfortunately the world is not just and consumer-hostile behavior often ends up being more profitable.