I think the reasons is because the competing airlines all realised that losing money on the route was not in their best interest.
If you want the cheapest option, consider these options:
- Cheapest "direct" may be with Delta or UA (I see UA and DL both for $1130+++ depending on dates SYD-IAH-SYD)
- Check NZ via AKL for some specials.
- Consider FJ via NAN
- Consider one of the cheap Asia carriers such as Korean or Air China (I see a fare for A$950+++ SYD-LAX return or to IAH for A$1250)
From past experience in 2007 flying FJ (Air Pacific) to LAX via NAN in Y, I don't recommend that option. AFAIK, FJ still have only two aircraft (both 747-400s) capable of flying that route - so if there is any delay or technical hitch involving one of them it is rarely possible to substitute another aircraft. This lack of redundancy causes cascading delays in subsequent flights that can take days to sort out.
In my case, a prior delay caused my flight from SYD to depart many hours late because the plane was several hours late arriving in SYD. This meant we got stuck in NAN overnight.
NAN is a distinctly sub-standard airport and the ground staff were very slow and inefficient. No one wanted to stay in the transit lounge because there were no amenities there, and spending the night in a hotel wasn't a viable option because it took us
hours to be processed through immigration and the hotels are a considerable travel time from NAN - we would only have had a couple of hours at a hotel before having to return to the airport. My wife and I spent a very humid and uncomfortable night in the departure lounge, and although we were each given a small (I think it was FJ$20) food voucher the only food available was both expensive & unappetising - some soggy pre-packaged sandwiches and a very limited range of fruit.
And on the return flights from LAX via NAN, althougn there were no delays the outside of my luggage somehow got wet with something that smelled like dilute sewage! I had to throw that suitcase out when I got home.
That said, the fares are very competitive, the FJ 747-400s are well-maintained and I found our flight crew to be excellent. So
if you're lucky enough not to be delayed or to have to transit at NAN you should have a pleasant trip - but I wouldn't rely on that if I were you.