that's very true man, and i wonder why it is so?
my guess would be it's because they train legs and back much less often than they did in the 70s/80s (once a week, rather than twice a week) and they also train them using MUCH HEAVIER training loads
With the increased size, especially legs comes the waist expansion, not everybody has bob paris genes for a tight waist and a thigh measurement almost the same size.
With the back, robby already had a great back, so did quinn and jorma raty, haney, bannout then christian, etc, but I think its also a case of someone achieves it, it becomes the standard and others try duplicate it within their means