The fundamental issue with MOND is that it purports to be a simpler model that doesn't require invoking the mysterious dark matter....except that it still requires dark matter to explain all of the observed phenomenology. MOND doesn't explain the observed gravitational lensing that we've seen, for example, so even MOND proponents admit that dark matter is needed to explain that. Similarly, phenomena like the bullet cluster are still explained by dark matter in the MOND context.
ThereOnceWasAMan t1_ixkhyoy wrote
Reply to comment by nonotan in Lopsided star cluster may disprove Newton and Einstein, controversial new study claims. An uneven distribution of stars in several nearby clusters may offer evidence of MOND — a controversial theory of gravity that disputes Newton and rejects the existence of dark matter. by nimobo
The fundamental issue with MOND is that it purports to be a simpler model that doesn't require invoking the mysterious dark matter....except that it still requires dark matter to explain all of the observed phenomenology. MOND doesn't explain the observed gravitational lensing that we've seen, for example, so even MOND proponents admit that dark matter is needed to explain that. Similarly, phenomena like the bullet cluster are still explained by dark matter in the MOND context.