Why doesn't the Ministry of Magic mass-produce Portkeys?

Question

I am well aware of the reason all of the authorized Portkeys have to look like garbage (Why are portkeys always made of rubbish?), but what I don't understand is why they can't be mass-produced.

Let me explain: it would be much simpler if the Ministry of Magic were to make some kind of unique object to be a Portkey. This Portkey could be easily enchanted to go somewhere at a specific time or whenever touched, like the one to the Quidditch World Cup and the Triwizard Cup. Then, they could put a simple Muggle-repelling charm on it, like the ones for the Quidditch stadium or for Hogwarts, and just duplicate them again and again. The Muggle-repelling and Portkey charm would stay on these Portkeys (just as the burning charm stayed on Hufflepuff's cup) and they would be much easier to find and use for wizards. This would also avoid the possibility of Muggles' memories having to be modified.

Answer 1

It can be done. But a generic argument against this would be that it would bring in a lot of hassles, which includes inventory problems, unauthorized usage, which can also put on a lot of work for Arthur Weasely's department.

1. Inventory Problems: As we all know that portkeys are junk. So, it is a huge hassle to store such a huge amount of junk just for later use. Instead, the current practise, which closely follows the Toyota Production System is far more efficient, due to less over-production, less stock-at-hand and less labour(/ man hours) required.
2. Unauthorized usage: From the books, it is clearly apparent that (most of) the magical folk are not as responsible as they need to be when it comes to using magical devices and keeping them away from the muggles. So, in spite of a muggle repelling charm, their over production would just bring in more headaches for Arthur's department. It wouldn't be long before someone says: Me having junk as my portkey? No, I want a diamond ring, and I'll pay for that

So, this would bring more problems than it can actually help solve, for the Ministry of Magic.

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