EDIT: Let’s cool it with the downvotes, dudes. We’re not out to cut funding to your black hole detection chamber or revoke the degrees of chiropractors just because a couple of us don’t believe in it, okay? Chill out, participate with the prompt and continue with having a nice day. I’m sure almost everybody has something to add.
The problem is Dark Matter is a theory that proposes specifically currently unobserved matter exists to solve our math problem. That’s not something we can automatically assume, imo. It’s looking highly probable, but not certain. It’s not just a blanket term for impossible to understand forces, okay, it’s not a pseudonym for C’Thulu, it’s a very specific solution among many.
Nobody “automatically assumes” anything. Dark matter is the best candidate of possible explanations because it explains observation and still fits the standard model. Even if they find the necessary particles eventually, nobody would call it certain though. Certainty is a unicorn.