The Internet actually killed bodybuilding. For a couple of reasons. 1. It diffused the information about drugs and spread the word to anyone who spent a week in a gym that all the pros were just walking pharmacies. 2. It took all of the drama out of it. No more waiting to see who won contests or waiting to see new pics. 3. What was once a very rare commodity, pictures of huge muscular physiques, became unbelievably cheap and common place, saturating the market and killing demand through oversupply. I'm sure there are many many more effects I'm too lazy to think of.
While this coincided with physique deterioration post Ronnie, it was more the cause than the physiques themselves.