This can be very useful for code using framework like Angular that annotate fields with @Input and @Output to tell semantic of given code. For example the just published Material widgets: https://www.dartdocs.org/documentation/angular2_components/0.1.1/angular2_components/GlyphComponent-class.html there is no way to tell which are actual input fields (the most important piece of API) from regular fields that are used internally by a component.