Why is it harder? Well, asking for a link is a positive thing. People like positive things. You tell them they have a great site, you are wonderful, etc etc. But link removal requests are negative and people do not like negative things. You are asking a webmaster to remove a link you have to them because Google thinks it is low quality. How dare you tell a webmaster their site is low quality!
Shai Barel of Brilliance said it worked well...
