"A logo is about identification, not communication." – Sagi Haviv
Whether you agree with this statement or not, developing a mark that successfully identifies and differentiates a brand requires a solution with a level of elegance not needed in any other situation. It's the ultimate confluence of so many (accurate) cliches - less is more, concept is king, keep it simple.
True, a brand isn't a logo and a logo isn't a brand, but done well, a logo should evoke emotion and, if possible, succinctly communicate what the brand strives to be.