It reminds me of comments here on HN which have very low scores: they get greyed out and effectively "disabled", like a disabled form field.

However, disabled form fields which demand no interaction, not even reading, from the user should not attract interest. It's fine to make fields which are unimportant less prominent.

As you say, real read-only content (such as the text on a web page) should both be easy to read, and not shown inside a user input control in the first place.