Well it's essentially just a placeholder name for what we don't know ;P

Along a similar vein, I find the concept of "Dark Energy" really hard to swallow. To me it seems like such a bizarre assumption to assume a force akin to anti-gravity instead of assuming plain old gravity.

Except that dark matter is often described as exotic and actually existing but not yet discovered. And I'm not talking about the publications that platform charlatans like Michio Kaku