Bodybuilding in general, along with many niche sports, is declining in popularity.
Unfortunately, financial pressures in the current North American environment has a lot to do with expensive pursuits decreasing. Although supplements and nutritional products are more popular than ever with the advent of 'cross-fit' and other fitness-as-a-sport activities, many people are just not willing to shell out their rapidly decreasing leisure dollars to attend or invest in this sport.
The other issue is that the era of people admiring the true freaks may be past, especially with the new physique division. There will always be the people who admire the leanest, dryest, biggest person on stage but the general public has moved past onto other things. Again, the 'Crossfit Games' brings more viewers online, attendees to events and participants then bodybuilding ever did, even in the age of Levrone, Flex and Dorian.
Those of us who built a passion for bodybuilding will argue these things, but eventually be faced with the realization that without multi-disciplinary expos such as the Arnold, highest level bodybuilding may have already declined into obscurity. I personally believe that every good thing that has ever happened in my life is due to training, and I know many can say the same.
Sad...