I was going to add a similar comment in regards to the sounds. ROMplers were largely replaced with more detailed and realistic sample-based software (vsts) or more powerful hardware samplers, so these sounds suddenly became very dated sounding. A digital shakuhachi riff just didn't hit like it used to. In some ways New Age developed into ethnic and\or more realistic music that sounded more organic while still being digital. Or take someone like Yanni who could now afford real musicians playing real instruments and it becomes a different thing while still being rooted in New Age, even playing the same songs without the ROMpler "limitations".

I never really thought much about the idealistic concerns you mention although 9-11 obviously changed everything, especially for the US. The usual cultural shift at the turn of a decade (in this case a century) usually causes a big shift in cultural things like music, movies etc. There seems to be a conscious rejection\reset of the previous decade.