I don't know who is "footing the bill", but the answer is obviously one of money, and who is paying for it. Ie it costs a lot of money to put those
Arabic channels up on a sat that can be viewed in the US. Nobody is going to spend the money to do that unless they can make money from it, which means either subscription services or advertising to a LOT of viewers.
Same is true going the other direction. The suggestion was made above that the few americans in the middle east "can watch most of the U.S. channels in there", this is hardly the case, and I doubt that it has much to do with the number of Americans over there. When you consider that there are thousands of TV stations in the US, and the fact that I'd guess that the only ones viewable over in the middle east are the major networks and CNN, which is just a handfull of stations, I really think there isn't as big a difference as is being suggested. Plus, US networks are of interest to more than just Americans over there, while very few Americans have an interest in non-english middle east channels (this is partly a symptom of the sad shape of US education with respect to only knowing English, but is also a symptom of the rest of the world wanting to know English because it is important to them in the business world). There are simply lots of economic reasons to put a handfull of American channels on sat over there, and it makes no economic sense at all to put thousands of middle east channels on sat here.