I'm going to write you off as a troll, since either you're not reading what's being posted, or willfully misunderstanding.
I replied to your comments above, where you suggested the user can sync content back to their Mac using an iPhone. I pointed out this is not a solution. Argue all you want - your proposed solution requires an additional device. I don't think that's an acceptable option.
Since you took the time to be huffy at another person in thread for being unclear, I think you need to check yourself, and your intent.
Let's level set:
1) The problem is that mac users, using itunes and cloud or match can only have one user at any given time on the system able to pull content to their system in the cloud. This means one user authenticates, gets content, and if another user logs into the system before the 90 period us up for the initial linking of the machine to apple, they will be refused. Even if user #2 is within their device count.
2) If it *is* greater than 90 days, the authorization token is moved to user #2. User #1 is now unable to sync content on that machine for 90 days.
3) MacOS X is and always has been a multi user system. Users who authenticate to apple's services have to provide a user and password for their iTMS account.
4) Thus the only constant in points 1, 2 and 3 is the actual hardware itself.
Workarounds suggested so far are:
1) Use a different music service that doesn't use a DRM scheme that ties to hardware for its cloud/match service equivalents
2) use an iOS device to sync back to the machine.
My point (again) is that users who have paid for their content:
1) Shouldn't have to switch services, as this isn't good for apple.
2) Shouldn't have to have another product to make the services they've paid for work.
I'm not sure how any of this is unclear, unless your intent is to argue semantics/pedantics and detract from the overall conversation.