The mix is being done on a large mix stage which is (at least) on par with a well equipped cinema. Or maybe it's better, using custom modified theatrical speakers, but the goal is to have a proper translation to a proper cinema. If the mix stage has a wall of subwoofers, capable of producing 10Hz with ease at a level we can actually monitor it, we might even use it in the mix. However the real world cinemas would start distort, destroying the experience, and nobody but us and a few homecinema enthusiast would be able to hear the effect anyway. So there is no reason for filmmakers to put in 10Hz material, it's even a risk if you do.
So why is it there anyway? It's mostly a side effect of the way we work. There are multiple ways to derive the LFE sounds. You can use dedicated fx sounds, directed solely to the LFE channel. You can use 'sends' from the main channel (sort of 'taps' if you are not familiar with the terminology), meaning you feed the LFE with the same information you feed the main channels, only filtered below a certain frequency. You can cross-filter sounds sending the mid+highs to the mains and sending the lows to the LFE. And for all these options there are additional techniques to enhance the signal, like sub harmonizers. To each mixer his/her own preference so it's not the same for each movie and it's not even the same within a movie. E.g. some mixers don't add LFE to music, some do. So if you 'send' some music to the LFE and the music contains some 10Hz frequencies (airco?), it will end up in the LFE. Same goes for sound effects (the main reason actually). If you pitch down a recording of a cat purring, playing it at 5% original speed, you might get a wonderful weird sound. But 200Hz from the original recording now is 10Hz. You can imagine a lot of sounds of fantasy creatures, as well as many sounds like underwater, airplane, space, weather, scifi, monsters, and even normal stuff like room tones, can be modified versions of regular sounds. So there is a good chance some 10Hz information will end up in the final mix. But there is an even greater chance it's not intended and not even noticed by the filmmakers in the first place.
What I've learned talking to a lot of hometheater enthusiasts is they tend to canonize the sound track of a film. As if everything you hear is what it should be and is intended by the director. (the sound dept. is never mentioned by the way). In reality the final mix is what it is because the film had to be released at some point. Filmmakers tend to do what they think is best using the time and resources they are provided. Given extra time the film would be different. This goes for all departments, though some departments suffer a lot more (like visual fx for example).
That being said, if you want the reproduce the 10Hz information, feel free to do so. I wouldn't mind (I didn't mix War of the Worlds though, let me be clear about that
). I'm sure the director wouldn't mind. We all want you to have a great movie-going experience and I damn well know a high end home theater can surpass the cinema or our mix stage. Even when "it's not what the director intended".
You are not missing out on anything if you don't though. And if you end up with some annoying continuous very low frequency rumble it's probably some bad engineering on our part