Nope, not the whole point. Therin lies some of the film's brilliance. One of the messages of the film is knowing when to follow the instructions and when to pursue radical creativity.
Following instructions or not are both acceptable in the end, there's no one right or wrong way. The issue with the dad/Lord Business was that he only allowed following instructions.
Saw it - much belatedly - a few days ago. Worth waiting for, and while I'd suspected the twist due to people hinting that a twist existed, it was still played out extremely well.
I'd like the sequel to have themes about segregation and hate, or something. Like, duplos are trying to be integrated into normal LEGO society, but all the normal legos hate them.
Key revelation for the closing act: Duplo and Lego can interlock.
Edit: Oh, one other thing. In the Old West scenes, they had a native american, a cowboy, a cop, a construction worker - and they *didn't* do a Village People gag?