[mike_hock]

And how is that a bigger problem than people using the filesystem any way they wish and putting arbitrary content in files?

[kevin_thibedeau]

The filesystem is manageable by users (with few exceptions). You can't easily discover which part of a registry hive is associated with an application.

[mike_hock]

It's precisely as discoverable as the filesystem. It's a tree like the filesystem. With names given to nodes by the application, just like the filesystem.