The <pre>
element allows styling which pre-pending a ' ' to each line
doesn't, which can be useful (and is used in places).
And inside <pre>, the {{template}} syntax doesn't work, while it works in
' '. This distinction might be important. (Whether this is a bug or a
feature, I do not know :)
It's a feature -- <pre>-in-wiki essentially means: <nowiki> +
<pre>-in-HTML.