I can agree that you will find a lot of people who are 'forgiving' of Apple on these forums, and not all of them work for, or have worked for Apple. As someone who has more Apple ID's then fingers on one hand - I completely understand the issues at hand. With the forced conversion from mobile.me to iCloud people like me, who have an old xyz@mac.com address that was moved over to mobile.me will loose the ability to recieve mail at the mac.com domain, adding further complexity.
To be fair to Apple, and the concept of "Macs just work" I still believe that to be generally true, Macs do, overall work with less hassle, more stability and far fewer Hardware and Operating system issues (not to mention Hardware VS. Operating system issues. The period of utility for the hardware and length one can use the MacOS for without having to reinstall the operating system due to the corruption of some master database that oversees the entire computers functionality is longer then anything I experience in the other camp. The Apple ID, its ability to be consolidated, merged or migrated has nothing to do with "Macs Working" and everything to do with the underlying systems of the app store, the music store, the web services (.mac / mobile.me / iCloud) and the interoperability that exists now, but was not planned for in the past.
I completely dismiss the complaint that the issue is DRM related as being an invalid and absurde attempt at mollifying or delaying the resolution of this issue, as the music apple sells now is DRM free. If I download a song that i purchsed in the past, that song is DRM free, so why would the DRM on those songs prior to the DRM free days be an issue.
The reality is - Apple needs to take this issue seriously! Despite some of the most creative ads out there, the real inertia expanding the apple market share is the cult-like community of users who have experienced the ease and elligance of apples product - and told others.