Re:This is oversimplified some of it plainly wrong (Score 1)

Dark matter does not emit radiation by definition. It thus has to have enough gravitational pull to keep all EM radiation in. That is a freakin big chunk of matter, not small gravity fields! And what do they mean normal and not normal matter... it's all the same stuff, energy. The energy is just "stored" differently.

This is a non-sequitor. The ionization caused the universe to be opaque. The creation of non-ionized matter (a lot of hydrogen and a little helium) allowed radiation to travel and the universe became transparent. We see the remenants of this as the microwave background. This has nothing to do with dark matter and gravitation. The dark matter merrily broke the symmetry presented by a flat universe and allowed `normal' matter to prefer certain parts over other parts. Read the article next time.