RPGMemes

Maybe. It's because "weapon attack" is the verbiage they settled on for hitting somebody with something that isn't a spell (spells make "spell attacks"). They could call them "weapon or unarmed attacks" but that seems unnecessarily verbose when 95% of them are going to be made with a weapon. You might think that for hand-to-hand combat you could simply refer to "melee attacks," but "melee" is a specifier that can be applied to spell attacks too, so it's out.

So the current situation is this: a rule can simply refer to all "attacks," or it can refer to "melee" or "ranged" attacks, or it can refer to "weapon" or "spell" attacks, or it can use both specifiers (as in "ranged weapon attack").

So if you want to fix it, you need a word to replace "weapon" that could include unarmed combat but excludes all spells. "Physical" might be good, but has some edge case problems: if I have a psychic "blade" that attacks your mind, it makes "physical attacks" despite being a non-physical object. If I have a spell that physically throws a boulder at you, it's pretty easy for me to remember that I should make a spell attack roll, but if you have a feature that defends against "physical attacks" you might think it should apply against the boulder when it doesn't. "Martial attack" might be getting at the right thing, but it sounds strange, and for new players who might be new to RPGs "martial" and "melee" are both uncommon words that kind of sound similar, and that might cause confusion. (Also "martial melee attack" sounds more natural than "melee martial attack," but then it has the opposite word order from "melee spell attack" and that's weird.)

There may be a perfect word out there, but in the end they decided "weapon" was the least confusing, despite requiring the caveat that attacking unarmed is a "weapon attack." And so everywhere that the rules say "attack with a weapon" instead, it is to specifically exclude unarmed attacks, although I admit that it's not always obvious why they want to do that.