E.T.Smith said:Put another way, the setting exists solely to improve play, But play is not about validating the setting.
I am not sure whether I do fully agree.

While we use our own setting, far from the OTU, this setting meanwhile
also has its own "canon". If a player wanted to do "Cool Thing X", and
this would be "kewl" but in open contradiction to our setting's "canon", I
simply would not allow it.
The internal logic and the consistency of the setting are, from my point
of view, necessary to have fun with the game. It helps with the suspen-
sion of disbelief, and it gives the players and their characters a reliable
base for their decisions and actions.
Therfore even we non-canonistas sometimes have discussions about
our setting's "canon", where we try to close some annoying gaps or
to develop a plausible future for a part of our setting ...
