Why would I want to use the registry?
As a programmer on a Windows machine, why on earth would I every want to use the registry, as opposed to simply storing appropriate information in the application data directory?

The advantages of using the registry, it seems to me, are fairly simple:

 1. Allow flags (file paths, etc) to be stored between runs of a program.
 2. You can back up the entire registry in one fell swoop.
 3. Follow standard practices of installation (a minor benefit, but when all else is equal, it's a good idea to follow standards).

That *seems* to be it (I may be missing something).

However, using the registry seems like a bad idea in the long term view, because registries tend to get cluttered with unnecessary program data, slow down computer startup, etc. Isn't it better to store program data/flags in a known file, because that can't adversely effect a user's computer?

Additionally, it seems like a developer has more control over a hidden directory, being able to store multiple types of data in custom files. Plus, there's the advantage of storing everything associated with a program within a single, easily deleted/backed-up folder.

What am I missing here? Why is the use of the registry so widespread, and what are the reasons for me to use it too?
Why would I want to use the registry?
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As a programmer on a Windows machine, why on earth would I every want to use the registry, as opposed to simply storing appropriate information in the application data directory?

The advantages of using the registry, it seems to me, are fairly simple:

 1. Allow flags (file paths, etc) to be stored between runs of a program.
 2. You can back up the entire registry in one fell swoop.
 3. Follow standard practices of installation (a minor benefit, but when all else is equal, it's a good idea to follow standards).

That *seems* to be it (I may be missing something).

However, using the registry seems like a bad idea in the long term view, because registries tend to get cluttered with unnecessary program data, slow down computer startup, etc. Isn't it better to store program data/flags in a known file, because that can't adversely effect a user's computer?

Additionally, it seems like a developer has more control over a hidden directory, being able to store multiple types of data in custom files. Plus, there's the advantage of storing everything associated with a program within a single, easily deleted/backed-up folder.

What am I missing here? Why is the use of the registry so widespread, and what are the reasons for me to use it too?