I think that there are or has been strong bodybuilders in all eras. I do feel however that in the "old days" strength was more highly regarded in the bodybuilding circles, maybe because there were less separation between bodybuilders and powerlifters. Nowadays both camps seem to be almost isolated if not almost at war with each other.
Now, Onlyme can correct me on this, but bodybuilders and powerlifters in the days used to train at the same places and pretty much the same way save for pre-contest (bodybuilding) or peaking (powerlifting) training. The biggest difference was diet.
Nowadays there are still some superstrong bodybuilders, but since strength doesn't seems to be as highly regarded guys who could really push-up amazing numbers don't really "go for it".
An example of a strong bodybuilder is Canadian heavyweight contender Samer Zebib who can incline bench press 415lbs for 12 reps 4 weeks out of a contest (in front of dozens of people, me included, and yes that was using free-weights, full range-of-motion, controlled reps). BUT I would agree that on AVERAGE bodybuilders back then were stronger, especially if we are talking about strength relative to bodyweight.