I think the industry went the lightweight route as another avenue to catch the consumer. Better machine techniques and new stock material all lent itself well to making rifles 2+ pounds lighter.
I remember a writer, I think Ron Spomer, wrote a Mt. goat article in one of the NRA magazines at least 7-8 years ago.
He had a little "wand" with half a kevlar stock and a bunch of holes drilled in the magazine box, bolt, etc.. I don't think it went 5 pounds all up. I know I saved the article.
Like all things, too much of something is not optimal. I believe a lot of grousing about the Kimber 84M's was due to people not familiar with such a lightweight and how to hold it, etc..
The pendulum always swings back to the middle, be it weight or cartridge.
