[notacoward]

It's true that indented code is different than text, but I don't think it's different enough (or in a way) to affect the conclusion. Indented blocks don't go on forever before the eye must seek back to the beginning. Width limitations help reduce "indentation creep" which is bad for its own reasons. Block comments (including those extracted for documentation) are often full width. For these reasons and more, a column limit yields more readable results.