Now, now (grandpa longneck is talking

). Disney's dinosaur certainly did not have the emotional value the land before time has, and certainly parts of the plot have been copied from LBT, but I would not judge it as harsh as you do.
One important difference is that in Dinosaur Aladar is born to an intact, healthy world which is later on destroyed by the asteroid. This also takes away a lot of the effect once they reach the nesting ground (nothing like the moment when Littlefoot first beholds the Great Valley).
The characters are different from LBT. We don't have any Krons or Brutons in LBT (unless perhaps if you want to equate Cera with Bruton) nor any characters whose age troubles them (Bayline and Eema), thus stressing the topic of social darwinism.
Of course there is no love relationship in LBT and no growing up of characters (which I think is a point that some (of you?) have spoken up for in LBT).
The animation of Dinosaur was quite beautiful and they also have some very nice music. I think they could have done much better, but the movie gave me more than it ever took away. So why should I detest it?
I think one problem of Disney's Dinosaur is that they sort of produced the movie before they produced the plot. There are many scenes (to be found among the bonus materials) which refer to totally different stories, some of which include a brother of Aladar, others his grandparents and other characters.
In fact even though the bonus material DvD offers only a short glimpse at some of those scenes (and tells very, very little about the alternative plots) I suppose they might have fared better with one of those plots as they seemed to be less like LBT or other stories we already know.