Every time I see someone ask, "does this belong on HN", I think exactly that. Obviously it was interesting enough for 200+ people, so if it's not interesting to you as an individual then you can move to the next article. It astonishes me how many people seem to think it's <Your Name Here> News instead of Hacker News.
That's wrong too though: if I get 1000 people who love professional cycling news to sign up to HN and start upvoting articles about Alberto Contador, that doesn't mean it's on topic.
It's wrong only if you assume that guidelines should pertain to an absurd range of deliberately destructive yet highly implausible scenarios, as opposed actual problems that could regularly occur in their absence.
My example is contrived, but if you think about things like the TSA, US electoral politics, and that sort of thing, it begins to look much more realistic.
The guidelines do specify a few things that might be interesting enough that they'll get upvoted, but still don't belong here -- "most stories about politics, crime, or sports", for example. Unfortunately, some people vote without reading the guidelines; it's up to the rest of us to use the "flag" option accordingly.