Experts say there are rare galaxies that act like they have no dark matter. I thought that was what put the end to taking MOND seriously. Isn't the whole point

Experts say there are rare galaxies that act like they have no dark matter. I thought that was what put the end to taking MOND seriously. Isn't the whole point to explain the alleged dark matter by some uniform rules instead of local conditions? But I never understood what started the interest in it. Everything I have ever read by proponents on the internet has resembled "believing in stuff (like "luminiferous ether") you can't see is unscientific". I have never understood the feeling that dark matter is illegitimate, because there are so many invisible things that we do take for granted, like radio waves. I have written similar things before and gotten lectured by anti-dark-matter-ites on why radio waves are obviously different from dark matter, but it didn't illuminate anything.