Thank you for the feedback Jonas. After speaking to the OneDrive team at Microsoft, they let me know that their use case for this would involve hiding the file input and just spoofing a click to invoke the file/folder picker. This makes me believe that perhaps there should be less of an emphasis on UI and more on providing the functionality that developers need. On that note, there is actually a 5th option that we can entertain. We could have three different kinds of file inputs: one type for files, another for directories, and yet another for handling both files and directories. This means that if a developer has a use case for only wanting a user to pick a directory (even on Mac OS X), they would have that option. This would also future-proof for Windows/Linux if they ever introduce a file and folder picker in the future. This kind of solution would be more additive in nature which would mitigate any heavy changes that could run the risk of breaking sites.