ONT, my former home airport, was very easy to use even when it was much busier. Ten or so years ago, DL had 767 nonstops to ATL. I'm told it's now like a ghost town. Part of the problem was indeed LAWA's failure to market it, part was the Inland Empire's economic problems.
The good news is that there is plenty of room for filming. Almost anytime you see a commercial set in an airport, it's ONT.