Back when I haunted the wizards of the coast forums a 100 years ago mentioning Katanas was a bannable offense because of how vitriolic and stupid the arguments tended to get. Similarly you ended up with really vicious argumetns about psionics rules. Some were genuinely interesting and there ended up being some great discussions/screaming matches about rules and the like. People get passionate about things or just want to troll.
You have me really curious now - what in the world is there to argue about in regards to katanas? Is it that they're somehow a superior weapon? That seems like an especially ridiculous argument in D&D - it's been a long time since I looked at stats, but I think as far as D&D is concerned a katana is functionally a longsword that takes a separate proficiency? Even if you want to claim it's somehow better, fine, make them all Masterwork by default - everyone is on the same page by level 5 or 6 when actual enchanted weapons start popping up anyway.
Ok, well there were several subjheadings to this. See in 2nd edition the katana was genuinely OP, it was something like 2d12 damage which for those that aren't complete geeks is exceptionally high for a melee weapon. Then they just made them masterwork bastard swords in 3.0-3.5. This had objections from four camps.
1) Katanas are way better than that, they can cut cannon barrels and should be proper high damage
2) Katanas are curved blades not straight and most curved weapons have a higher crit range but maybe adjust damage, plus if you have to take an exotic weapons feat for it it should maybe be better
3) Katanas are trash and so are you ya damn weeb, they should be doing barely any damage and quit bringing your anime trash to my game
4) Katanas should have their own category if we're going to do the same thing for other similar weapons that exist or make tons of exotics, might as well make it more in line.
1 and 3 had the loudest and most pronounced arguments and all of this was pre-mythbusters. Some people might have been looking at it as legacy rules, some were going off of mall ninja lore, some were reacting negatively to what they viewed as foreign ideas in their gamespace, some were reacting to stuff from the past and some on both sides were trolling. I ended up in it by accidents because of a discussion about exotic weapons in general and what a crapshoot they were. I ended up making them their own thing and the stats I used ended up being the stats for them in Pathfinder a few years later so I guess I was ahead of the curve.
Also weapon stats could mean a lot because of how certain builds worked, a weapon that has poor damage but stupid high crit range due to typos is nuts for any kind of crit fisher build. But I'm already probably boring others that aren't into this so I'll stop here