The interesting thing here is that most of the trolling victims are Nintendo fans. Maybe that was intentional, who knows.
Regardless, if I may treat the question seriously for a moment, I would say that Nintendo's biggest weakness is that they react very, very slowly to emerging trends, if at all. There is really nothing wrong with incorporating the successes others are having into what you're doing. There seems to be this stubbornness about Nintendo, this feeling that they don't want to follow the methods others have used, even if those methods are extremely popular and wanted by the fans. I still think that the old guard at Nintendo grumbled and pouted for weeks when people started clamoring about this "online" element, or those new fangled "CDs".