Hi Fragile,
A very interesting thread, and I'd tend to agree. I am now 37 and have been listening to Prog for over 20 years, and feel that my tastes in lyrics have changed over that time. I was never into mainstream 'Sex, Drugs, R&R' style lyrics personally, but have long grown tired of fantasy(Ayreon) / satanic (Sabbath)/ emotional turmoil (Evergrey) lyrics as well.
I have always been interested in semi-political lyrics, but these days don't mind Christian lyrics, such as Morse/ Glass Hammer providing they aren't too pushy, which I would have shyed away from before. Of course songs about Brain Stem Surgery and War in Bosnia are very interesting when they are done well, and quirky lyrics such as 'Late for church' by Magellan (which is on at the moment) always brighten up an album for me...