[MikeMacMan]

I don't besmirch LEGO for doing what is an entirely rational for them: design products whose pieces, like puzzle pieces, don't have much versatility outside the context of that playset, leading children to tire of them quickly and want a new set.

Of course, LEGO still sells the general-purpose sets with instruction books to show you how to construct dozens of different buildings/vehicles/etc. My son prefers those, but every kid is different.

The No Girls Allowed theme is pretty easy to explain: mass-market films of the type that will have product tie-ins are almost universally aimed at boys, and LEGO is simply downstream from that trend.

There are toys that give kids' imaginations some exercise, and there are those that, like video games and Harry Potter LEGO sets, don't deliver quite the same workout. It's up to you to cultivate in your child a healthy appetite for the former.

EDIT: I would add that the Toy Story movies do a good job of echoing the nostalgia that adults feel for those older, simpler toys. My son and my affection for those movies has in some way conditioned us to stretch our imaginations and breathe new life into old toys.