These are those different features. Delphi / ObjectPascal for example support either. As for what benefit - your example with Ruby can be reversed and I can as

These are those different features. Delphi / ObjectPascal for example support either. As for what benefit - your example with Ruby can be reversed and I can ask you the same question. Anyways large part of a programming is an art and different people have different approaches. If you do not like the concept do not use it. Just do not assume that what you think is the "right way".