I know what you mean WWW, but I don't know if I'd agree totally with that.
Your hearing is one of your body's most easily damaged assets. Most training aircraft's (C152 etc) cockpit levels are well, well above SPL levels that will cause hearing damage, the more protection you can get the better (to spend 45hrs + on a PPL course in a old C152, wearing poor ear protection won't do you a lot of good). If your hearing is OK then you'll still be able to hear the engine fine, even with an ANR headset.
As a side discussion though, in 'higher-end' GA aircraft, with far quieter (modern design) cabins, I guess there could be a danger that a decent ANR headset could make the engine noise so faint that it couldn't be heard (dangerous situation?).
Best regards.