Why is it "magic user stuff" to craft a magic hammer? Other than tradition, there's no real compelling reason to say that a fighter can't make his own magic weapon. The last Avengers movie showed exactly what it could look like with Thor essentially holding his hand (well his whole body) in the forge so they can make the new weapon. Crafting a magic weapon is only "magic user stuff" because that's the way it's always been.
Thor did not craft his own magical axe, he went to get Peter Dinklage to craft a new magical axe because of course you would. He was not Thor crafter of magical axes after all. Although in the end we find out that Thor does not actually need a magical axe because, like the power of love, the magic was inside of him all this time.
And, well, I'd say you missed the larger point. We're arguing about whether or not a fighter should be able to do stuff at very high levels that a caster can do at much lower levels. In 5e, can your 15 strength character jump 20 feet using skills? Maybe. Depends on the DM and the dice. Oh, you're a caster? Go right ahead, no problems, no DM adjudication and no chance of failure (Jump spell, fly, and I'm sure there are other options). For some, this is a pretty large issue because it strongly narrows the narrative space that you can use unless you play a caster.
Sure, "I" am missing the point. The Fighter can jump 20 foot all day, every day and twice as much on Sundays while the Magic-User better damn well hope that they thought of prepping that Fly or Jump or whatever Piss off the Fighter spell in the morning instead of anything else more useful if the party gets jumped by gawd knows what monster. Because nothing says power like the ability to get past something that a grappling hook, a 50' rope and a Strength check can do just as well.
Now the interesting thing to discuss is what is the Fighter going to give up to get his plot coupons? Every other character class has to give up something so what is your magic axe crafting, ravine jumping, arrow blocking Fighter going to give up for his powers? The Thor character in the Avengers does not give anything up, even Groot had to sacrifice one of his arms to craft the magic axe but Thor loses nothing.
Of course, 5e solves this problem by making pretty much everyone a caster, so, that's one solution.![]()
I guess they just copied the 4e solution in that case.