The problem with Lion I think is slightly different, and as someone said, even if we are no here to say who's guilty and who's not, I understand why some users are angry, and feel that Apple fooled them.
When you switch from XP to Vista and to Windows 7, you know that you are doing a major upgrade, you know that a simple upgrade is not recommended but you'd rather do a clean install, and you know that it will radically change your habits. Windows does warn everywhere to make a complete backup before doing anything.
Now I'm not saying Windows is better, not at all. But with Lion, Apple made people think that you simply have to upgrade from the app store, with no warning regarding backup, and never ever mentioned that features would be removed, or that some programs would be incompatible. The user is supposed to know ? No, there are different types of users, not everyone is a geek. Finally, even me, a Windows power user, therefore used to backup everything before a major upgrade, really was defenseless, as I saw Lion as a simple upgrade, and I still see it this way, as the OS barely changed in my opinion.
Just take Autosave and Versions. Yes Apple mentioned it, but did they mention it would completely remove the simple "save as" feature ? No, they did not mention it. Many professionals can't even use there Numbers files anymore, too scared that Lion will modify them without notice.
So yes, Lion is at its first version, and no software is bug-free. But Apple has to keep in mind that you do not advertise for an OS as you advertise for a simple app. Before installing Lion, a huge Warning screen should tell the user about softwares and features that might cause problems. But it seems like Apple has issues when it comes to admit that everything is not that easy in the Apple world.
A satisfied Mac user, a satisfied Windows user, and very unsatisfied Version user.