What Caused this Change?

I find it so interesting that in many of the different texts addressing the issue of the use of hymns verses the more modern choruses, the old hymns are referred to as doctrine-rich and sacred, filled with Scripture and the Gospel and the vivid descriptions of who God is. The authors behind these hymns were intelligent, fervant individuals, who must have known God in a way none of us can even imagine.
What has happened in our generation and society and in our churches that has made us throw away these sacred texts for completely vague and insignificant ones filled with worthless, empty fluff like our "praise choruses" seem to be, that could be written by anyone, and directed toward anyone or anything? What has changed our view of God and our relation to Him so much that we now are always putting Him into whatever mold we want so that He is who we want when we want Him? I don't understand what exactly has brought this generation to this shift in thinking that is so subjective and individual, and so contrary to the teachings of the Scriptures.