I'll admit, I hadn't considered that there might be a bigger divide at higher levels (currently, a sword that deals 11-12 damage is the equivalent of a two handed sword that deals 14-16, level-wise). If it does get significantly wider, then I'm wrong.
That said, dual wielding still offers you two sets of stat bonuses, while the two handed weapon gives you one. If the damage is as close as that reddit post says it is, I'd argue two handed is still on the weak side when compared to dual wielding.
If dual wielding gets more stat bonuses from magical items, more dodge chance, and damage that is just slightly lower, shouldn't two handers get a bit more than slightly higher damage?