That sounds like a severe lack of perspective.
FWIW, your definition of "halfway decent" would exclude most software shops in the world.
It is extremely unprofessional to disable or ignore warnings such as the "unused function parameter" warning
Unused function parameter warnings are often noise (e.g., due to #ifdefs, unimplemented APIs, backward compatible APIs, etc). I agree that code should compile w/o warnings, but the benefits of tracking down and squelching unused function argument warnings are pretty marginal in my experience.
"-W -Wall -Wcast-align -Wstrict-prototypes -Wmissing -prototypes -Wpointer-arith -Wshadow -Wsign-compare -Wformat=2 -Wno-format-y2k -Wimplicit -Wmissing-braces -Wnested-externs -Wparentheses -Wtrigraphs"
Update: Forgot the most important one ... -Werror. Making warnings equivalent to errors is the only way to ensure that they're always taken care of.
The benefits of tracking down and squelching such warnings would have very likely caused this bug to never exist. The point is that you make "compiles without warnings" a policy, and you build a habit of maintaining that policy -- after a while it begins to take almost no effort at all.