*sees a thread about 'arms and armor'*
"Huh, wonder if they're silly enough to rehash the usual bosh about katanas."
*opens thread*
"Yup."
*closes thread*
The thing is that there's so much myths surrounding Katanas that it elevates them beyond a mere weapon that was perfectly suited for the given battle tactics and enviromental scenarios into Mythical Überweapons that are capable of leveling entire buildings just by being drawn out of their sheaths. Now, some people think that leaving that particular image untouched is harmful for the general understanding of History in the most objective way possible. Thus, they explore historic backgrounds of the Katana and come up with reasons why they totally did suck, but instead of bringing enlightenment to the myth-consuming masses like they wanted to, they start zealous arguments that are kinda pointless and silly with neither side giving way, creating a stalemate that is doomed to last forever.
Without their shields Roman swords would be of not much use.
Also the classical "throw a pilum at that dual wielding barbarian at point blank".
Yep, that's what the entire Roman Strategy was built as. the Shield Wall technique, with the pilum being used to thin out the charging enemy armies, then intercepting the mass of the people invading with your mighty shields and chopping your opponents up with your Gladius. The only bad thing about this strategy is its weakness to flanking attacks, but that was countered by using either Auxilia or more legionarries, and in later stages of the combat, if the situation was favourable, the legionarries stationed at the sides would move towards the mass of enemies in the middle, trapping them in a pincer movement.
Chopped bits of the Germanic Tribes, anyone?