MoonSong
Rules-lawyering drama queen but not a munchkin
You know what, let me put it another way, because this really does bother me. I'm a linguistics student. I'm working on a couple of conlangs. I taught myself Python for the express purpose of writing a script that could phonetically generate and process words to my satisfaction.
Woow, you are into conlanging too? That's so cool.
This is a very inaccurate generalization. Even the the underlying assumption you make that there was something called a "feudal system" is increasingly questioned by historians. And in the times and places where there was a professional martial class, status was still determined by birth, connections, and command ability. Yes, William of Normandy could swing a sword and ride a horse, but he became the Conqueror because of politics and an army, not because he was the most badass swords-and-horseman.
Basically I would say that for every William the Conqueror and Richard Lionheart in history, there were tens if not hundreds of badass warriors that died in disgrace and without of crown.
I think they haven't expanded on Magic Item Creation because they are attempting something of a "Hippocratic Oath" ('first, do no harm') in regards to crunch in this edition. (Not saying they are successful, but I think it is pretty clear that they are being cautious.)
They've left magic item creation in the hands of DM-fiat because only DMs have a clue of what is happening within their respective campaigns. What will be necessary in one game could unbalance another. What will help some DMs build an interesting challenge in one game could be a tool to wreck another. Yes, we could be disappointed in that our work is not done for us, but we could also be happy that we were not given a problem.
One size does not fit all.
But many DMs are very reluctant to try stuff without the proper scaffolding to support them. What we have is too bare bones for that.