Improbable sounds immensely better than pointless. As for "mindless" why Naminé don't think that it means the lack or absense of a mind. Simply, it stands for "requiring little mental effort." Either way, Naminé doesn't see a point in "arguing" with Mr. Aragornbird when in reality, he and she are in complete agreement outside the choices of words they used.
Naminé haven't watched FLCL herself, as she is severely anime deprived. Though, if what Mr. Kazuhito said is true about all the necessary foreknowledge about the anime is required, then perhaps it's best for her not to watch it so she won't take a mislead negative impression of a great anime to heart then.