This raises some interesting questions—especially in the area of decision making. In short, our rational choices aren’t so rational. From studies on choice to ﬁrst impressions, neuroscience is exploring how the brain works—and it’s kind of scary. We’re not nearly as in charge of our decisions as we’d like to believe.
You've probably seen the research studies where nice-looking ATMs cognitively 'work better' than their uglier, but equally competent cousins. As real-time brain imaging becomes available to researchers, it's seems that the mind forms many 'rational' decisions first emotionally and then creates logic to match.
I think there's probably more to a Mac than just the computer — it's the culture of trust that users place in the interactions which enables them to try something on a whim. When users are rewarded with successful dragging between applications, they try it more. When modifier keys have reliable 'concepts' like "The Option key makes my action apply to other similar things", users are more likely to try them. This is becoming more and more of a moot point as Windows has improved over the years, but the cultural lag, I believe, means this still applies more to Mac users on average.