Liberals find the "root cause" meme a convenient alibi to avoid holding people responsible for their actions. If people are responsible for they do, their background doesn't excuse them from the consequences of the choices they make. Since liberals think people are basically good, if they do something wrong, its their environment or upbringing that made them go bad, not something they did of their own accord. We'll never see "root cause" disappear from the liberal lexicon because that would mean blaming minorities and women and they are never going to be demanding people be the best they can be. That would cut liberals out of the picture.
"Show me just what Mohammed brought that was new, and there you will find things only evil and inhuman, such as his command to spread by the sword the faith he preached." - Manuel II Palelologus
Undeniable truth about liberalism #1:
Liberalism, at its core, is the use of force to force the innocent to pay for the consequences of those who make bad decisions.