When and why did people start using backwards smilies?

I first learned about smilies in the early 90s, on BBSs.  I learned that a happy smiley is :) and a sad smiley is :( .

But in recent years, I've seen people doing their smilies backwards.  So if they want to make a happy smiley, instead of  :) they put (:  .You have to tilt your head to the right instead of tilting it to the left.

Having used smilies for 20 years, I don't tilt my head any more.  I just skim and quickly process a) the fact that a smiley is present, and b) the direction of the parenthesis.  So when I see a backwards happy face like (:  my first thought is that it's a sad face, because for the vast majority of my life a smiley with a left parenthesis has been a sad face like :(

How did these backwards smilies come about?  Why do people think they're superior to regular tilt-your-head-left smilies?