I love Lego... so why should I watch an hour-and-a-half ad for it?
This "documentary" is little more than a long ad for Lego. Of course it's difficult to say bad things about Lego, and I don't think the filmmakers should have done that, but even the tone of this film is focused on advertising and marketing. Somehow, it is overly positive about a good thing. The company's influence on the film is very clear, right down to how they only refer to Lego as "Lego bricks," which is how the company recommends you talk about their toy.
Maybe Lego is just not interesting enough for an hour and a half documentary?
Lego is great. It's too bad you can't make a great documentary about it though, apparently.