And how much growth potential is there in selling Active Directory, Excel, and Exchange?
Every sizable company already has these things installed. Smaller and new companies may choose to spend their dollars elsewhere and that's a change of events for Microsoft. Projects that previously would go on Sharepoint are now done less expensively with cloud services, for example.
In tech, growth is in consumer, and with consumer tech drifting in to the enterprise, even enterprise IT spending may not go to Microsoft.
You can't really blame people for abandoning sharepoint, it's really an excellent display of why you shouldn't try to interbreed all your gui applications with internetexplorer iframes.
It's literally the worst MS have ever produced.