For me, the beauty of Lego was just a huge bin of interconnectable parts that I used to make whatever my imagination came up with. For my kids, Lego is pre-built model airplane set that they build one time and then display. I liked my Lego better :)
Makes me think there could be a big cognitive difference when playing with Lego as well, for example, divergent vs convergent thinking.
Maybe Lego needs to manufacture sets that are just "collections of bricks". In fact, I think they did that at least for a while. I know my past self would have loved to have a few sets that when put together would provide the kinds and variety of pieces used in books such as The Lego Play Book.
You can still buy LEGO Classic which is just a bunch of bricks.