That argument with field/particles is not right. MOND isn't adding arbitrary new position-dependent field like dark matter hypothesis does. MOND changes the uni

That argument with field/particles is not right. MOND isn't adding arbitrary new position-dependent field like dark matter hypothesis does. MOND changes the universal law of gravity. That is a priori much better thing to try. Yes, there is arbitrary interpolating function there (so also a great degree of freedom to fit the observations), but the resulting modified law is supposed to be universal, valid for all points of space and all material particles. Dark matter hypothesis, on the other hand, just adds immense number of new obscure quantities(dark matter density at all points of space) that can be tuned to fit (almost) anything.