While some of the audience will be because of that, I doubt the majority are. Last time I checked, Facebook's mobile site actually degrades fantastically well, all the way down to old Nokia feature phones. You can bet that in many countries that is a big deal.
Bingo. Outside of Tech Companies/Silicon Valley/Major US Metro Areas/the US as a whole, iPhones don't have that huge a market share. More people have Android phones, but often running old hardware, old software, and even more have feature phones. If you're reading Hacker News, forget that you're not a typical user at your peril.
