File management in Finder uses the system-wide pasteboard APIs. If you place something on the pasteboard with Cmd+C, you can paste it in any app that supports f

File management in Finder uses the system-wide pasteboard APIs. If you place something on the pasteboard with Cmd+C, you can paste it in any app that supports file pasting, and get a context-dependent result. If you paste the file in Terminal, the file path is entered. If you paste it in Mail, the file is placed as an attachment. If you paste an image file in Photoshop, the image is placed as a new layer. It's a consistent system. Now, what should happen if you "cut" a file with Cmd+X and you paste it into Mail? The file is deleted from the original location, but still somehow attached to the email? There's no point in monkey-patching such a feature into macOS for the sake of appeasing recent Windows converts. It's like complaining why Pascal doesn't support braces instead of begin/end. It's a different system. Feel free to not use it.