One of Linus's key strengths is that he's good at listening to people and honestly evaluating new ideas based on their merits. Good code goes in, bad code stays out. He's not an ideologue like Jobs or Lucas. He's a pragmatist, and that's what makes him a good BDFL.
In the example of Lucas, the organizational structure is only at fault in so far as it allowed Lucas the creative control to make bad decisions.
But that is generally a level of control we want from movie directors or software projects. The criticism was of how the power is wielded, not that the power structure exists in the first place.
Torvalds is amazingly good at what he does, and if someone doesn't like his direction, the code is all there for the forking.
So, yes, a dictatorial model can accomplish good things, if the dictator, like Torvalds, is smart enough to delegate as much as possible and actively avoid making decisions. Torvalds being smart enough to pick smart underlings is the second half of that puzzle.