Nothing has been stripped from the Community Edition.

An extension for Professional Edition will provide enhanced granular permissions capability.  While the current implementation is very robust, there is room for enhancements to support more targeted scenarios which are not applicable to all users.  By taking advantage of the extensions model we are able to provide a very robust default implementation but also create extensions to meet the specific needs of Professional Edition customers.  This model also makes it possible for others to extend this functionality for their own unique needs and in a way that is supportable (ie. does not require modifications to core code).

The extensibility of the platform makes it possible for every user's needs to be served, without sacrificing their ability to upgrade in the future.

Scott Willhite, Co-Founder DNN