Malte, you took the words out of my mouth. Partly to drive home the producers' lack of enthusiasm (and to raise fanfic ideas to anyone in that market) here are a few missed opportunities:
1) Bron seems to bear no resentment whatsoever against his herd for failing to free him. Pretty forgiving of him. Did the herd do anything to help Bron before leaving the lava river? It shouldn't have been hard - Litlefoot and his friends were able to do it easily. The cynic in me wonders if the herd was actually glad to be rid of Bron. Oh wait, perhaps I spoke too soon. The bird-like dinosaur does tell Littlefoot that Bron sacrificed himself to save everyone else. But what made them think he was dead? In fact, here's an idea. Have a faction of the herd decide that they don't want Bron as their leader anymore, and try to stop Littlefoot and co. from saving him.
2) giving Spike some development. They fleshed him out a little bit in the 8th movie, but there was only so much that could be done, given that Spike can't talk. Why is he still mute? The trait was fine in the 1st movie, but it shouldn't have become part of the status quo immediately thereafter. At the very least other characters should have tried to address the problem in the sequels. Strangely, Spike does get one word in the 5th movie, but the event is immediately forgotten.
3) I only caught a glimpse of the resolution to Littlefoot and Cera's quarrel (NB: I haven't watched the movie, just a review of it by an Internet critic), but it felt painfully contrived. The pair didn't realize their mistakes or got over their grievances; the plot just demanded they make up. Why not make the rift permanent (at least as of the movie's end), and in the process have the gang break up? As a bonus you could have them fall in with new friends in a sequel. I know that Littlefoot and Cera never truly made amends in the 1st movie, but the story ended before they could do so.
4) The group's fall into a cavern river and over a waterfall could have been a dangerous, exciting scene. Instead, it was presented (perhaps intentionally) as the dinosaur equivalent of a theme-park ride. While I'm on the subject of danger, I want to gripe about the sandstorm. I don't mind that the makers didn't incorporate the breathing difficulties that real-life sandstorms can create. The four main characters present being dinosaurs (and kids), they probably wouldn't have known the proper measures to take, and that would have been the end of them. But the scene could have been played for thrills in other ways. Ex: the characters could have ended up separated really far away from Littlefoot, they could have stumbled into a crevice or a sharptooth (imagine how cool a sandstorm chase might have been) or Ducky could have been blown miles away from the others.
5) Once every movie, Littlefoot sneaks off to go on an adventure. Why don't the adults remember this and keep an eye on him? Why don't they scold him when they meet up at the end? You can't just ignore continuity but then observe it in other respects (for example with regard to Bron).
Come on Universal, where's the enthusiasm? Where's the ambition? I know that your top priority is profit, that the target demographic is kids, and that kids aren't particularly demanding. But still, why not give them movies that in the long run will raise their standards? Why not give them viewing fare that challenges their brains and moral values? Is that too much to ask for? By the way, I'm sure I could spot more missed opportunities if I watched Journey of the Brave, but that unlikely to happen anytime soon.