@Petrie I just had an epiphany

!
What if they argue and whine so much because this:
Before they came to the great valley, they lived in separate herds. They're used to living with themselves and seldom communicating with other dinosaur species. Meanwhile, there's always sharpteeth and other calamities in the mysterious beyond it's a wonder that all the dinosaurs didn't go emo or something. Hmm.. in fact, maybe they struggled to survive so much, that they didn't think too much of higher things.
Now picture this. After the long arduous travel to the great valley, they finally arrive there. And after a while, they realize the peace and abundance of food and (relatively) little problems to deal with. At least predatory problems that is. They now have more time to think about what part of this luxury resort they want to call home, so maybe there were territorial disputes (just a thought). But anyway, with the dinosaurs in a much closer and CONTINUED (remember that part!) proximity to each other in safety, they not only learned things about other species they might not have known before, but were also able to think of 'higher' things more often since they weren't, y'know, struggling to survive. This is probably what lead to the plot on LBT3. I just think the dinosaurs found it hard to get used to each other. This was kind of similar in other sequels when they'd bicker over things. Each dinosaur has a completely different look and sometimes even purpose (take a longneck compared to a threehorn and tell me the differences). I don't think it was just racial (species)discrimination (if that) but also the fact that these neighbors lived so close together and with continued proximity (as well as the whole "this is my turf" attitude). Since these are animals, I kinda think this was very.... dinosaur-like I guess. Sure, the great valley is big, but eeeveryone goes to the waterhole/river
Though they sure learned a lesson after LBT3

... hopefully XD