So I too love the idea that we don't need dark matter to explain all the gravitational effects we observe in the universe. However, is it just me or does the falsification of this seem a bit sketchy: if we find a dark matter particle...then my theory is false. That's a bit like saying...oh yeah if we find a different way to unify general relativity and quantum mechanics...then String Theory is false. It seems like there should be a 'smaller' way to falsify it.