One reason is ambiguity, this is an extreme example but shows a bit of the issue: http://en.wikipedia.org/wiki/Lion-Eating_Poet_in_the_Stone_Den http://en.wikip

One reason is ambiguity, this is an extreme example but shows a bit of the issue: http://en.wikipedia.org/wiki/Lion-Eating_Poet_in_the_Stone_Den http://en.wikipedia.org/wiki/Lion-Eating_Poet_in_the_Stone_D...