This dates me, but I find most young people nowadays more tolerant, more "live and let live," and open to a far more colorful range of interests than most of my peers were at that age.
And I think this "new mellow" has little to do with all the loudly trumpeted and ideologically driven emphasis nowadays on tolerance, diversity, etc., most of which actually serves the interests of intolerance and ideological conformity.
Back when I was young -- let's face it, we're talking 40 years ago here -- there was a narrowness, a rigidity, a sour curdled meanness to so much of the culture, at least as I experienced it as a kid growing up in small-town America. Depart from the norm, let yourself be drawn to any interest that was at all colorful or out of the ordinary... and you would be inundated beneath a tidal wave of white hot scorn, rage, and withering self-righteous indignation. There was a time when Sinclair Lewis's Main Street was very much a reality in small-town America.
But something has changed. Today's young people are by and large light years more "live and let live" than I remember from when I was that age. And it's not an ideologically driven or ideologically linked openness and tolerance; it's genuine, unforced, and quite broadly and impartially dispensed. I must say, I find it a breath of fresh air.