I disagree. "Stuff that matters" was frequently applied and upvoted as a tag to articles during the period of time when article tags were more editorial than they are now. This was quite some time ago. Not to say that no one felt as you describe, but I think an equal number of people, at least, took the interpretation I described.
Also, I didn't mean to imply that the site creators intended for the motto to be applied in the way I described, just that it was applied that way in many cases.
The point is that sometimes making the rules a little fuzzy can allow a community to moderate itself more flexibly and prevent the "lawyers" from taking over. HN is similar, where though there are loose guidelines, the rules for appropriate content are (deliberately, I believe) kept vague.
