I think that the Bastard sword argument is flawed because if you spend a feat on weapon focus with a sword you will get the same damage bonus or better. However this does not stop Greatswords smelling of wee. If you compare a Greatsword with a Greataxe you get lower average damage and much lower damage on critical (higher damage dice + high critical) at the cost of +1 to hit. If you wanted a higher crit with a Greatsword it would cost a feat and yet still deal less damage than a Greataxe on a critical!
To be frank one-handed weapons are even better, as a defender you want to be attacked by as many of your opponents as are not being "controlled " as possible, so the monsters are not hitting your "strikers", so in effect you gain the effect of your shield from 1 or more attackers i.e +2 against each attack as opposed to a single +1 to hit or damage. This effect is further compounded as often you will be attacked by minions, meaning your bonus damage has literally no effect at all but you will still take about 10% less damage.
I hope they can errata the major flaw with Greatswords just being "bad" . I was considering saying that you only get heavy shield proficiency with one-handed build but with a Two-handed weapon build you automatically gain power attack. This would help balance the options in my opinion as you are not paying for two virtual feats that you do not use (or at least very often) with a two-handed build and gain something in return.