I remember claims that, by now a couple years ago, cell phones would cost $10 and the batteries would last for weeks.

My phone dies in 3 days if I have bluetooth on, and it cost $60 for the one-step-above-dirt phone after a 2 year contract got me a discount.

Also, how many people do you think are "well advised" of safely using security features? Even simple ones? Who don't see Facebook as one gigantic privacy / security geyser? ie, non-security-aware-geek-types? This is a minor, arguable security improvement and a major feel-good for people who don't know any better, and not much else.

You say that most people don't understand security, and unfortunately, you're exactly right. So why do those who know better intentionally choose to make things /less/ secure but market it as /increasing/ security?

I don't see how perpetuating the problem (every phone device is going to be insecurely logged in within the next 2 years) moots the concern. "Everyone does it!" is no excuse for a poor security model.