I think this is a USA legal environment vs. everybody else's. USA carriers are based in a place where people are more inclined to pursue legal remedies for minor mishaps, even imagined ones.

That said, I did notice that when flying local airlines (QF, NZ, Ansett) in Oceania, the pilots were very quick to turn off the seat belt signs. Occasionally, it seemed as if the signs were off as soon as we were beyond the end of the runway.