According to the Philadelphia Inquirer: 

http://www.philly.com/philly/news/local/22998759.html

Basically some agricultural interests and breeders oppose the bill.  They are willing to let cruel practices exist because they think it might affect their bottom line.  I am very disappointed in the Amish/Mennonite community who are responsible for many of the abuses.  It should make anyone wonder about buying food items from the Amish since they raise dogs in such filth.  I tell my friends to do no business with the Amish and in the farmers' markets let them know that and  why.