I think Arabic is charming,and now I'm studying Arabic on my own.

Thanks to globalization, certain languages are superior to others. And a superior language entails a superior culture. No matter how complex a language is, that doesn't mean it will have a value of its own on a global scale. The power of a language is determined by those who speak it. It's a matter of power and who has it. As much as I hate to say this, the Arab world isn't contributing much to the rest of the world and is undergoing an economic collapse, except for the Gulf states. Oil-producing countries are still dependent and consist of consumerist societies. I live in Saudi Arabia, and out of all the non-Arabic speaking expats I know, only a handful speak some Arabic, and they can still manage without it. In restaurants, shopping centers, etc., you don't even need Arabic. Heck, you might not even be understood if you spoke only Arabic. So if residency laws in Arab countries don't oblige knowledge of the Arabic language, it's perfectly natural to see expats who have lived for 10 years in an Arab country and still can't form one Arabic sentence. Besides, the most popular stereotype about Arabs and Muslims these days is that they're violent terrorists. It's unfair, but it's reality. Many people don't want anything to do with that region. 

Arabic native speakers are nearly half a billion. However, languages usually take their (Learning) popularity through the cultural development and the economic power. And most of the Arabic-speaking countries are neither this nor that.. except some oil-producing countries, which ,in general, don't concentrate alot about the language issue. e.g, you can live in Dubai without the need to know how to speak Arabic because English is speaked everywhere there...

That's what I think why Arabic "learners" are not so many ... 

English is the most widely-spoken language in terms of geography; because the British, who conquered most widely, spoke English. They colonized North America, parts of South America, South Africa, India, Australia and New Zealand. English is the dominant international language in communications, science, business, aviation, entertainment, music, radio and diplomacy.  English likely will become the most-spoken language in the world at some point surpassing Mandarin.  Most languages in the world, including English, use a Latin-based alphabet.  It's easier for most people to learn another language that uses a similiar alphabet as their own native language, such as English, rather than Arabic which uses a different alphabet.  The Arabic language has no chance to become as popular globally as the English language.

I think because we r so affected and blindlyfollowing otherS