Every time some random Dunning-Kruger slashdotter displays his ignorance to the entire Internet, a kitten dies somewhere.
In astronomy and astrophysics, the term "dark" doesn't mean the same thing as it does in common english, just like the term "metal" doesn't mean the same thing as it does in common english. Astrophysicists and astronomers use the term "metal" to describe any element that is neither hydrogen or helium. To them, there is hydrogen, helium, and metals, which include things like carbon or oxygen.
In the same way, astronomers and astrophysicists use the term "dark" to describe anything that has observable, and even measurable, effects but has not been demonstrated to fit in any current theory. There is no "dark" matter and "normal" matter, because "dark" matter is "normal" matter in all the current hypotheses about it. No astronomer or astrophysicist claims, or has ever claimed, otherwise. They know there is unaccounted for mass in the universe because they can observe it and even measure it through its gravitational effects on stars and galaxies, but they have no current theory on what this mass actually is, only hypothesis. Hence their use of the word "dark".
The same thing applies to dark energy. They observed that the universes' expansion is accelerating, and according to the current theories of physics such acceleration requires a force, but they have no current theory on what this force is, hence their use of the word "dark" force, or more commonly dark energy.
JFC the worst kind of ignorants are the ones who are convinced that they know better than thousands of people who've worked and studied in a field for decades and add on knowledge that's been accumulated for centuries. For fuck's sake, stop killing kittens and shut the fuck up when you don't know what you're talking about.