Thank you to those who have responded to this musing. Although small, the response has been balanced and informative.

After reading the replies, and reading up on MooseX::SlurpyConstructor, I would say that having the StrictConstructor behavior as a default, with an opt-out capability, would be a Good Thing(tm).

From what I can tell, SlurpyConstructor was meant to be a less painful way to transition to MooseX::StrictConstructor in as much as one could include SlurpyConstructor and then issue warnings or take other steps if the "slurpy" attribute contained anything. This would of course presume that someone was paying attention to log files or emails.

Personally, I'd just as soon go straight to StrictConstructor, test everything I could manually, and make changes as indicated by the exception messages received and be done with it. It is difficult for me to envision a use case where the "slurpy" behavior would actually be desired as part of a proper design.

I doubt that the change I am advocating will ever occur given the amount of existing code in the wild now, but I hope that this has given those in the Moose Cabal, along with others, food for thought.