No shit. Anything can be a weapon.
The point is, some things, like firearms and samurai swords, are specifically and explicitly created to be weapons.
That this fact may inconvenient to your lifestyle does not make it untrue.
And I would not dispute that.
If I dropped my house on a mass of people, that would be pretty devastating.
Still that does not change the fact that an AR15 is a weapon even if it went straight from the store to hanging over your fireplace till the end of time.
You kind of stepped in some mud, there.
Table knives of all kinds came about after a ban on sharp knives in eateries and during feasts a very long time ago.
Before that, people just used whatever daggers or utility knives they were carrying. They could have blunted them to comply, but that would be stupid. Separate, cheaper knives were purchased to be blunted, as a result.
Didn't take too long for establishments and organizers to purchase their own unsharpened blades, to be issued at the table. It saved a lot of frustration, and also opened the world to the concept of walking off with someone's cutlery.
The end result of all this was eventually the folding "pocket knife". It was a way around it all, that allowed one to carry a "weapon" into such events more covertly, and at the very least skirted the law at the time; which had no way to account for folding knives.
A butter knife, and indeed table-related cutlery of all kinds, is nothing more than a weapon blunted. Doesn't actually stop it from being deadly, but if you sharpen it back up, it's much more nasty.
...and by all that's holy, man; there's no such thing as a "samurai sword". It's a Japanese Sword. Their own word for it translates
directly to "Japanese sword": Nihonto. They have no need to differentiate between them, beyond tacking something at either end to identify excessive length variation.
A samurai was primarily a ranged unit, and when in close combat, as any other soldier in history, used pole-arms as primary weapons. Swords were side-arms.
Interestingly, they were one of the first (and only) cultures to develop culinary-specific cutlery without being
required to do so. Probably had something to do with all the seafood.
Japanese knives and swords are thick and heavy in relation to almost all others. They aren't particularly good in the kitchen.
So, if you're referring to a santoku or similar developments, I can dig it. A steak or butter knife? Nope. Those are always going to be weapons first.
Cheers,
Kennith