"Whatever!" is not an argument.
IF it is NOT used as a shorthand metasyntatic variable
for the basic randomness of the universe and an
acceptance of both entropy and the consequences
of ignoring Darwin;
then it is merely slang for
"HI, I'M REALLY STUPID AND I'M PROUD OF IT!"
Sure, I understand that teens brains aren't functioning fully
because they aren't yet completely developed (medical fact)
but parents can still make an effort to control them and
encourage them to learn their native language and
attempt to use it when their lips are flapping in public.