There is no doubt that the quality of the fishery is directly related to fisheries management and control. Unfortunately, most of the Departments of Natural Resources (different names in different states) in our country focus mainly on trout and bass, with much less focus on the panfish population.
Obviously, this is because of the ROI for the state's coffers (it's all about money!). CPR helps, but is not necessarily the total answer. Slot limits and enforced creel limits are paramount to any successful fishery. in my opinion. I can see no real reason/excuse for a one day creel take of 30 - 40+ crappie. But that's probably just me.
Shore fishing is less of a problem obviously, due to access limitation, but large creel limits are also to blame. Most anglers would rather keep larger crappie and bluegill for table fare, releasing the "dinks". This is not a good thing, but difficult to control. No one thing can be pinpointed as the increase or decrease in quality for a single fishery. Many factors are involved. JMO!
"A voyage in search of knowledge need never abandon the spirit of adventure."