IIRC sets used to have instructions for multiple models you could make, which helped to support the idea of making different things. My kids want to make the model and put it on the shelf - they're deaf to my protestations.
The instructions are good at teaching you a variety of ways the bricks can be used, help understand how to make larger structures from them, etc. And hell, following the instructions is fun, too.
They still do sometimes—they even have a line where every set has instructions for 3 different models.