The world of books allows us to walk in the shoes of people who lived in other times and other places, who belonged to other races and religions. It allows us to become more humane and open-minded. In exposing us to prose of the highest level, it encourages us to think in a way that isn't merely "better" but is more fanciful, creative, poetic and expressive. It makes us less boring, and less bore-able.
The poll is silly, but the quote is great. =)
When people ask me why I read, I tend to say that I read for entertainment - which isn't untrue. But entertainment encompasses so many things that the statement as interpreted might as well be. Learning is entertainment. Pleasure is entertainment. Seeing through new eyes is entertainment. Discovery is entertainment.
And this quote, well, it's a far more accurate answer than, 'I read for entertainment'.