Why is there a lack of OSS Back Office Apps? (Score 1)

The most successful OSS ventures have been focused on infrastructure needs (operating systems, networking, file serving, web serving, etc.). We haven't seen the same type of success with back office applications like accounting, ERP, supply chain management, asset management, warehouse management, etc. Is there something inherent in the OSS model that is preventing investment in back office OSS applications? Will we ever see successful OSS ventures in the back office?