If that's truly opposing what Lego is good for, then why does anyone buy Lego sets to build specific things with instructions?
This is just generating different sets of instructions; it's no different conceptually than downloading a PDF of instructions from someone online and building that.
I understand what you're saying, but as someone who spends most of the undirected Lego time with my daughter struggling to figure out what to build, I'm going to suggest that you have fallen into the trap of assuming that the way you do things is "correct" and not simply "the way I do things."
People build sets all the time, that's not odd. What's likely is that my son would like to build some set, where we've never bought it but already have the pieces.
Why scan a pile of Lego and suggest projects, when you can also have a robot build those projects for you?
In fact, why not 3D print a finished piece designed by AI?
You still get the fun of cleaning up mold lines for the AI, unless they build a robot for that.