[rozab]

I think it strongly evokes a line on a paper form, which indicates a place where the user must fill out a field (and fits with the recurring paper metaphor). If I'd never used a computer before, I think I would figure this out based on the context clues.

So while it may not fit current UI paradigms, it might be better? I applaud Material Design for attempting to move things forward in this way.

[thefounder]

The issue is that the computer screen is not a paper form. You can't just fill out forms wherever you see dotted lines/horizontal rules(hr tags). Unlike paper pages, most of the HTML pages are read only / not content editable.