Someone goes and builds a bridge. The bridge collapses because they applied mathematics in a way to maximise profit, with a safety margin just beyond what they can get away with by existing regulations. 5 million other bridge engineers also do the same, so that eventually bridge engineers get a bad rep, and people think bridges are awful awful things. This doesn't mean mathematics or quantitative analysis is at fault - and in fact these tools can be used to examine the incentives and other social dynamics that led to these situations, to be able to fix them more effectively in the future.
no, not of gravity or dark matter.
As for dark matter, the reason we don't have a good idea what dark matter is, is that is has almost no effect on normal matter. So the reason why we can ignore dark matter everywhere except at the frontiers of physics is, that dark matter only matters when one spends awesome resources to try to detect it.
Actually I thought yesterday about how to misconstruct a human detector for photos, one possibility would be to have face detection and then measure the average pixel color of the face. That would get me probably quite nice detection rates if I test on a dataset that has a racial markup as the average CS lecture. The thing here is, that I push the false negatives purposely to people of color. It is not hard then to invent a story about how 'mathematics proves' that black people are more similar to apes than white people.
We currently just don't have anything to ground models of human interaction in,^1 and what is worse most people treat models just as previous generations treated prophecies. They don't understand math and believe in it because they don't understand it.
^1 I am actually not saying that models are worthless, I am saying that most complex models only show what the author wants them to show and they can be as easily manipulated as an essay.