The downsides of having both strict and non-strict mode: - It is a maintenance burden on the compiler/interpreter writers to allow both modes - There may be u

The downsides of having both strict and non-strict mode: - It is a maintenance burden on the compiler/interpreter writers to allow both modes - There may be unexpected behavior when you use code from two different sources; one that expects strict mode and the other expects non-strict mode - There may be interpersonal conflict when developers working together prefer one mode over another