A funny thing happened today...
So I was in a convenience store, and "Wish You Were Here" came on the overhead music. Two young guys who were standing at the cash register started singing along, and then I started singing along and so did the last customer and the gawky guy at the counter! Of course we all stopped after a few lines out of embarassment, but there were were, but the thing was... I was the only person in the store old enough to remember when the song came out, and Pink Floyd was a popular band that got top 40 play!
I don't think that in 50 years, people not yet born will be singing along to today's pop music in public. Music companies just aren't giving bands like Pink Floyd a chance to be popular.