Massimo has addressed this previously so it might be best to search the postings. Python programmers should definitely be careful about the use of exec but Massimo has made a very conscientious decision to use it. There are tradeoffs and many feel that the design decisions Web2py has made are beneficial. Dismissing a framework solely on the basis of the use of exec is extremely short-sighted.
The poster really should go into details when making such a blanket assessment.
