I disagree with that view of Hippies. Today the term is Hipsters which is where the term Hippie came from. I'm not sure what to call the "save the earth" people.

The defining thing in the mid to late 60's was the Vietnam war, the draft and the soldiers (former classmates) who came home in body bags and this spawned the hippies and the music as well, it was a great time for music.

At the time unless you were enrolled in college with a full schedule or married you were going to get drafted and go to Vietnam. The draft boards were very corrupt, selecting the poor, black and those who had moved. The youth felt that they had no control over their lives. Starting a career was not possible because the draft was going to yank you away for two years, perhaps life. I got my draft notice, was examined, deemed fit, and when my induction letter arrived in the mail I "dodged" it—I joined the Marine Corps that day. Every thanksgiving I play "Alice's Restaurant".

I was not a hippie, I had a business designing and manufacturing electronic hardware. We made fun of the hippies but underneath that we were at least a little bit jealous.
 
I think this hits the nail on the head, from "Country Joe and the Fish:
Come on mothers throughout the land,
Pack your boys off to Vietnam.
Come on fathers, don't hesitate,
Send your sons off before it's too late.
You can be the first one on your block
To have your boy come home in a box.