Windows Vista happened and Microsoft still exists. And many other products from huge companies failed hard. I think these things are quite common for large companies. The fact that it's Apple just makes it more interesting.
Honestly, Windows Vista was a victim of the computing landscape of the time. Virtually none of what made Vista hated was changed at all to Windows 7, except by then everyone's PC had caught up to what the OS expected or they were going to stick with XP until the bitter end.
