The ending fizzled (SPOILERS)

The ending fizzled, IMHO, mostly because of the airplanes falling out of the sky. Until then, it was plausible that Leonard and his cohort were just crazies who were manipulating current events to terrorize the dads and their kid.

There's almost no rational explanation for airplanes to literally tumble out of the sky -- even a plane that loses its engines at altitude can glide for some time, they don't crash in a spiral. So the airplane crashes ended up being too much confirmation that there indeed was some kind of supernatural event taking place, Leonard and his cronies were, in fact, prophets of some kind.

Had the "apocalypse" events been capable of other explanations or on an already-extent timeline (the tsunamis), the whole question of whether Leonard and his cronies were just nutters would have been harder to decide. It also would have made Andrew's death seem more ambiguous -- was he just getting sucked in, or was he right?

Especially if the diner TV news scene had provided rational explanations for the apocalypse events or managed to downplay them (the Oregon tsunami, not as bad as shown, a forced perspective, etc), leaving Wen and Eric in a much different place in terms of wondering whether what they had experienced was this supernatural judgement or whether it really was just crazies.

By ending it with some confirmation that Leonard was right all along, the movie seemed to fall flat at the end.