Emotion makes good lawyering darned near impossible. People can't by nature control their emotions. Cool, rational thought is the only way that you can make a calculated decision, either on a cost-benefit level (as a client), or a tactical level (as an attorney). When emotions get in the way, rational thought goes out the window, and people start to fight battles for the sake of fighting battles. This phenomenon goes a long way toward giving family law attorneys a bad name.
Lawyers need to be held to a higher standard. They need to keep emotion out of their dealings with clients and with the system, but they can't banish it altogether. Emotion can be very valuable if you can keep it in control- it's called compassion.