I would have loved the kits when I was a kid as I had no idea where to start (I'm very creative now I think)and always built the same few things, although admittedly I was always at someone else's house so had limited time. Ha just realised I never owned lego as a kid, poor me!
I have bought a few kits for DD - she likes structure plus I do think being able to follow instructions is a skill that all kids need. Afterwards she uses them for free play. I think it's all good, different types of play build different skills.
I'll admit to also buying the girls kits because DD can't resist the prettiness of it all. She's saving for a chima kit too....