When I was a kid, there was 3 years between Star Wars films, and we got around 20-30 new Star Wars figures between films. We also were willing to go to the theater several months after release to view it again, because Star Wars could stay in the theaters for a year or more. With the PT, we still had 3 years between each one, but the toys had increased exponentially. Having 1 a year has really cut down on anticipation. The large amount of sets and such has really cut into things too. Brickheadz, buildable figures, micro fighters, 4 releases of sets a year as well as multiple UCS per year that don't have a set life cycle are eating away at the urgency that people once possessed. Plus, the average cost per wave has been going up. Not only are the individual sets more expensive for their size than previously, but also, the lower cost sets have been pushed aside for a higher percentage of larger sets with the slack being made up with the offshoot brands.
I think a part of the malaise is also due to the over-diversification. Hasbro has a number of lines releasing the same figures in different scales, Lego is releasing Star Wars in 5 different styles. We're getting away from the core of what makes the series collectible. People who were completionists are now forced to make a decision about which of the lines are most important and some are just throwing up their hands in disgust. Where I might have bought every set from a given release cycle, I am now being much more selective. Some sets will only make it into my personal collection if I spot them heavily discounted.