To be fair it can be balanced in a lot of different ways, like parry efficiency (stamina usage) and/or partial damage mitigation, so that chip dmg goes through.
As for using one handers only, that is indeed an option, but considering it is "just" a weaker two-hander, I do nto see the benefits, besides as I wrote earlier it was more for a rogue character.
In the end if someone really, really likes a certain weapon they will with it, but I believe it is fairly restrictive, the way it is now.
I would prefer to have a choice between using dodges and parries, instead being forced into one playstyle, but maybe that is just me