I’m building off the answer above for my reply: if the demo bores some players and entices others, then the demo has done its job of giving players a sense of whether or not they would enjoy the full game.
Personally, I appreciate longer demos when the file size isn’t too big. Like, there was a game last week I considered, but 500 MB was too much to try out something I might dislike from the first few minutes. Otherwise, for reasonable downloads, it’s nice to get more to explore.