Why won't the franchisor negotiate the terms of the franchise agreement?

It is important for the consistency of branding and customer experience that all franchisees within a system operate the business in the same way. For this reason all franchisees must have the same set of rules and guidelines which they need to comply with. On a purely practical level, if every franchisee had a different set of rules that they needed to comply with it would be a logistical nightmare for a franchisor to remember what rules applied to each franchisee.