"Come all you beasts of the field, come and devour, all you beasts of the forest. Israel's watchmen are blind; they are all ignorant; they all lack knowledge; they are mute dogs; they cannot bark; they lie around and dream; they love to sleep. They are shepherds who lack understanding; they all turn to their own way, and each seeks his own gain." Isa. 56:9-11b NIV

Not only was Isaiah prophesying to a divided kingdom, but the hearts of the people were divided as well. Some continued to worship God, while others worshiped idols. Isaiah was one of the few remaining prophets calling for repentance and obedience to God. The nation continued in idol worship and rebellion against God. The answer as to "why" is in these three verses. Isaiah cites a failure in godly oversight and leadership. The watchmen were spiritually blind and could not see the coming judgment. The dogs were mute and, thus, could not give a warning. The shepherds were without understanding and preoccupied with gaining wealth for themselves. We, as a nation, also stand in peril of judgment because of a failure in godly leadership.