Wide bandwidth = necessary?

Hi folks, there is one paradigm that bothers me a bit: many experts and audiophiles are stating that Red Book technology is outdated because of it's bandwidth limited function. I've read the human ear is capable of perception of frequencies beyond the normal human hearing, up to 40kHz. But this is only with live music! When listening to recorded music there is a restricted bandwidth because many microphones can only pick up frequencies up to 20kHz. So why the need for more and more bandwidth with regard to digital sound reproduction technology? What is not present in the recording can't be heard either, even with very wide bandwidth music reproduction gear.
What is also laughable is that many vinyl adepts say that phono playback gear can reproduce tones as high as 40kHz and that is one of the reasons phono playback sounds more "natural" than digital playback. This is a bit of a contradictio in terminis because most LP's are very band limited (30Hz to 16kHz is quite common). Your comments please.

Chris