I can't for the life of me understand why anyone wouldn't want it...
How about the fact that it costs money and is non-standard? A lot of us already have a domain and hosting service with FTP and other standard access methods, which we already pay for. MobileMe serves as Apple's excuse for not implementing proper import/export of settings. E-mail filters are a great example. Apple makes users dig into system subdirectories and copy a plist around between their systems. That's "elegant"?
Apple pretends to be surprised at the most basic functionality expectations. Again, E-mail filters provide an example: iOS doesn't even have them. Really Apple, in an era when 90% of mail is SPAM? What kind of fantasy world does Apple live in, where no one gets 10 screenfuls of spam daily, and it's fine for mobile devices to be cut off from the world around them?
The more you look, the more infuriating Apple's squandering of potential is.