Empty list as default parameter

[Paul Rubin]

bokr at oz.net (Bengt Richter) writes:
> Yes. The bindings of default values for call args are evaluated at
> define-time, in the context of the definition, not at execution
> time, when the function is called.

That's always seemed like a source of bugs to me, and ugly workarounds
for the bugs.  Is there any corresponding disadvantage to eval'ing the
defaults at runtime as is done in other languages?