Dark matter is not "Bunk Science"... But it has problems

Physicists say that 80 percent of the mass in the universe is dark matter, and not only this, dark matter is supposedly all around us, we just can’t see it. Sounds pretty crazy, doesn’t it. Indeed, every time I mention dark matter, I get flooded with comments about how silly the idea is. “Fantasy folly.” “bunk science,” “epicycles,” “a mirage”, “unscientific,” and on and on it goes. I really feel for astrophysicists, but those complaints are not totally wrong.