The James Bond "shaken not stirred" thing was an in-joke. Ian Fleming loved his traditional martinis at the Dukes Hotel in London and would never approve of such a thing.

Incidentally, the reason to stir and not shake is not about temperature, but about dilution. Gin watered down with little flecks of ice is just not a good drink. Gin served straight out of the freezer with just a drop of vermouth meanwhile is actually rather nice.