Some of the biggest problems have been CAUSED by Symantec anti-virus stuff.
Symantec products for Mac started their downhill trend even before OSX made its debut. But after OSX, Symantec has been horrid. And when you consider that Symantec cut its teeth on Macs in the early days....it's kind of sad. But when you consider that the number of problems out there affecting macs, and the fact that even past loyal customers quit using Symantec products because they caused more harm than good.... it's no wonder Symantec has been quietly backing out of the Mac development front.