I agree, it's fine to point out holes in a theory without an alternative explanation. However, it does still leave the problem of how else do you explain all th

I agree, it's fine to point out holes in a theory without an alternative explanation. However, it does still leave the problem of how else do you explain all the dark matter observations. So one must be careful not to give to much weight to those kinds of criticisms, as finding one hole in something that explains ten observations doesn't give much confidence in saying the whole theory is wrong (just an example.) Dark matter still seems a much better explanation than MOND to date, even if I personally feel it looks like a hack.