An interesting conceptual article with limited practical use. However, the author does caveat the baggage of EXEC commands.

Using this requires explicit permissions for users at the table level since EXEC does not maintain ownership chains.

The database design is no longer abstracted and must be continually published to a larger user community instead of a corporate data model.

Supportability by an IT department is compromised. Performance can no longer be guaged or predicted since SP behavior would change. In a DB that resides on a shared server a poorly performing user built statement could adversely impact other systems.

Not to mention all of the other benefit derived from the use of stored procs. No recompiles....