2h are actually the "best" weapon category and in particular 2h swords (In terms of effective killing power per encounter). Go to a duel server. Why do they proliferate there? It is because 1-1 they are the better on average and to the extent that battles are a sequence of 1-1 encounters, the same will apply.
With larger battles and decent teamwork/tactics, the utility of 2h decreases because of heavy cavalry/lancers and especially archer spam.
If anything, the speed of the 2h swords makes sense, although their cut damage can be absurd at times from a realistic standpoint. They do not need to be nerfed though.
