it's expected that you play within the existing
marketeer-created universe
Maybe that's how you or your kids play with them, but here we have no problem kitbashing the branded sets. Their parts end up in the color-sorted bins along with all the rest, and the kids build crazy stuff out of whatever. The last round included parts from a city, a dinosaur, and a submarine, and those were just the ones I recognized. We even mix Megabloks and Duplo with our Legos. Now, if I could only get the kids to pick up the parts when they finish...
Kitbashing is _the_ plot driver of the Lego movie, in that it's what Master Builders do.
Notice how the Lego Club magazine highlights people's creative builds.
I want to postulate that Lego's endpoint is not static sculpture, but active imagination. Consider fan fiction. Sometimes we want to create stories inside someone else's universe. Hasn't your imagination been sparked by some favorite movie or book or artwork? Have you ever wanted to tell the rest of the story? I know I did! That's why I flew my Duplo Millenium Falcon around the living room. I don't see how a more realistic version would have been less fun, or less imaginative. And that's the point of the branded sets. They're fun! With any luck someday soon I will be able to build model rockets that look a lot like what explodes on my launchpad in KSP, only my kids and I will be able to fly those around the living room, pretending the sofa is Planet Klystron, home of the savage (but peaceful) race of Mer-mole-men (Lego people with frickin' sharks heads!) Meanwhile, Superman arrives to rescue our stranded Kerbals, whose ship (naturally) blew up upon launch.
And so on.
It's about the stories we can tell ourselves and each other. In-universe. Something wholly new. It doesn't matter. Do whatever it takes to get you or your kids' imaginations jumpstarted.
Or at least that's what I'm after when I buy a Lego set (branded or not). It looks cool, and it sets my imagination racing.