Because the best theories have not identified dark matter after decades:
Having been fooled once, scientists have to ask: Is dark matter the new ether?
For decades, a few rogue scientists have stood hopefully at the edge of respectability, offering their theory called Modified Newtonian Dynamics, or MOND. Essentially, it says that physics doesn’t work as we know it at the largest scales. It says we’ve been drawing the wrong conclusions, and dark matter isn’t required to explain the universe. No one has managed to develop a theory of MOND that adequately explains the universe around us, but it occasionally gains converts simply because the competing theory of dark matter has a glaring flaw: we can’t find it.
Perhaps we’re wrong about something in the standard model that defines how the tiniest particles in the universe behave and interact, and dark matter exists, but in a very different form than we’re expecting. Or perhaps we are wrong about the laws of gravity.Korey Haynes, “What is Dark Matter? Even the Best Theories Are Crumbling” at Discover
“Best theories are crumbling?” We live in odd times when such news excites no great interest. It’s almost as if no one believed those theories much anyway.
Maybe the most current cosmology can offer is unbelievable alternatives to things no one wants to believe, for example, that the universe shows evidence of design. If so, if this field is in any way relevant to that problem, finding a new source of misdirection will become the goal.
See also: Experiment to probe the weak points of the Standard Model of our universe
Researcher: The search for dark matter has become a “quagmire of confirmation bias”
So many research areas in science today are hitting hard barriers that it is reasonable to think that we are missing something.
Physicists devise test to find out if dark matter really exists
Largest particle detector draws a blank on dark matter
What if dark matter just doesn’t stick to the rules?
A proposed dark matter solution makes gravity an illusion
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Proposed dark matter solution: “Gravity is not a fundamental governance of our universe, but a reaction to the makeup of a given environment.”