Extensions are predefined mapping to the executing program. There is no real concept of compatibility there. Useful for media files where you e.g. pick your ima

Extensions are predefined mapping to the executing program. There is no real concept of compatibility there. Useful for media files where you e.g. pick your image-viewer-of-choice, less useful when the script file already has a very strong opinion as to the expected executing binary. Compatibility can be hinted at, but really only determined on the application level. If the script runtime binary then looks at the filename and does something differently based on it, it's likely not correct, and if it is done, it'd better be because of some necessity. The "we prefer it this way" is not a necessity. Plus it breaks conventions and expectations. Enforcing file name extensions at execution, because you want to help an editor figure out how to lint or highlight the file, is also, arguably, letting a specific use case affect something it shouldn't.