That should be obvious... the overriding motive for corporations is profit. There's not enough of a arabic-speaking market in the US to support the channel.
There isn't a channel dedicated to watching people read, either... "Read TV, all readers, all the time" doesn't exist cuz there isn't a market for it. There's no grand anti-literacy conspiracy keeping it from happening.
Google for 'occams razor' before reading hidden agendas into things where simple solutions fit.