It was #2 for the year and wildly profitable. So, no I am not doubting there where plenty of people who loved the movie. The movie was above average and that's the problem. Hollywood depends on movies like The Sorcerer's Stone, The Fellowship of the Ring, A New Hope, Bourne Identity, even Iron Man to drive future revenue.
Movies that build off of that success make money, but they don't prime the pump.
Especially since the former is targeted at broad appeal, while the latter is more specifically a series of children's movies.
Also, "The Land Before Time" was a Universal Studios product (per Wikipedia), not a Disney product, so the starting approach is very different.
You keep comparing "Star Wars" to "The Land Before Time". I think you vastly underestimate the popularity of Star Wars, particularly the past 2 movies.