I don't think we should. There's a few reasons.
We're still in a mess with designer reasons: lots of people are over-sensitive to determining a question is designer reasons, but really the only thing that wasn't working is “explain to me their thought process behind why they did that.” The mod team has had to reopen a lot of questions incorrectly caught ...
The comment formatting section of the editing help pages lists all the available shortcut links you can use in comments, including [help] for the help center. As of posting that is:
[meta] – link to the current site's Meta; link text is the site name
(e.g. "Super User Meta"). Does nothing if the site doesn't have (or
already is) a Meta site.