There are a lot of factors at play that both agree with and challenge your statement.
Of those factors, the first two prominent ones I can think of:
- it could be that as an aficionado of flash animation, your tastes are changing as you view more and more flashes - what used to be entertaining is now dull because you've seen it so many times. Looking back at animations from the early 00's, I only remember the good ones because I didn't care for the bad ones, and they were still pretty numerous.
-it's becoming increasingly easier for users to get their hands on flash, in my opinion anyway. This may contribute to a growing number of new users spitting out 1 poor animation and then calling in quits, though this still happened in the past.