I found this video over at Beervana. Ken Grossman talks about declining hops in macro beers over the last couple of decades.
Of course, for us craft drinkers 15 or 16 IBUs is still a very low-hopped beer, but it's interesting that even beers that aren't considered hoppy at all (like, say, my beloved hefeweizens and sweet stouts) will have in the order of 20-30 IBUs. That lab testing indicates that macro beers are literally hopped in the single digits shows just how mild those beers really are.
I wasn't drinking beer twenty years ago, but I've heard anecdotes of older folks talking about how back in the day Coors was the most flavorful beer around. Even stories about smuggling cases of the stuff across several states when it was only available out west. The evidence of the lab testing would seem to indicate that by the standard of 1985 or whatever, Coors was indeed something special.
Also, posted without commentary, there's this old Keystone ad from the nineties.